diff --git a/ChangeLog.adoc b/ChangeLog.adoc
index 2b4de3fbd..4000ebb53 100644
--- a/ChangeLog.adoc
+++ b/ChangeLog.adoc
@@ -15,6 +15,7 @@ For a list of important changes that require manual actions, please look at rele
 
 New features::
 
+  * core: add variable `${highlight}` in option weechat.look.buffer_time_format (issue #2079)
   * core: convert option weechat.look.hotlist_sort to a list of fields (issue #2097)
   * core: rename variables with creation time in hdata "hotlist": "creation_time.tv_sec" to "time" and "creation_time.tv_usec" to "time_usec"
   * core: add unique identifier "id" in buffer (issue #2081)
diff --git a/po/cs.po b/po/cs.po
index 1b0e6d338..c9520386b 100644
--- a/po/cs.po
+++ b/po/cs.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:32+0100\n"
 "Last-Translator: Ondřej Súkup <mimi.vx@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4282,10 +4282,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "formát času zobrazeného na každém řádku v bufferu (viz. man strftime pro "
 "specifikaci data/času), barvy jsou povoleny ve formátu \"${barva}\", "
diff --git a/po/de.po b/po/de.po
index 6fe34a226..13c0a8659 100644
--- a/po/de.po
+++ b/po/de.po
@@ -26,7 +26,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-07 11:51+0100\n"
 "Last-Translator: Nils Görs <weechatter@arcor.de>\n"
 "Language-Team: German <kde-i18n-de@kde.org>\n"
@@ -4800,14 +4800,28 @@ msgstr ""
 "(prefix), Präfix und Nachricht (prefix_message)"
 
 #. TRANSLATORS: string "${color:xxx}" must NOT be translated
+#, fuzzy
+#| msgid ""
+#| "time format for each line displayed in buffers (see man strftime for date/"
+#| "time specifiers, extra specifiers are supported, see function "
+#| "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
+#| "you can use colors with format \"${color:xxx}\", see /help eval); for "
+#| "example time using grayscale: "
+#| "\"${color:252}%H${color:243}%M${color:237}%S\", the same with "
+#| "milliseconds: \"${color:252}%H${color:243}%M${color:237}%S.%.3\""
 msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "Format für die Uhrzeit, die in jeder Zeile eines Buffers dargestellt wird "
 "(siehe man strftime, welche Platzhalter für Datum und Uhrzeit verwendet "
diff --git a/po/es.po b/po/es.po
index 95c3f770f..97e5d8083 100644
--- a/po/es.po
+++ b/po/es.po
@@ -22,7 +22,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:32+0100\n"
 "Last-Translator: Santiago Forero <santiago@forero.xyz>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4399,10 +4399,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "formato de hora en el registro (ver el manual de strftime para los "
 "especificadores de fecha/hora), se pueden usar colores con el formato "
diff --git a/po/fr.po b/po/fr.po
index bc80c2120..cade61189 100644
--- a/po/fr.po
+++ b/po/fr.po
@@ -21,8 +21,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
-"PO-Revision-Date: 2024-03-15 19:18+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
+"PO-Revision-Date: 2024-03-16 09:39+0100\n"
 "Last-Translator: Sébastien Helleu <flashcode@flashtux.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
 "Language: fr\n"
@@ -4698,19 +4698,30 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "format de date/heure pour chaque ligne affichée dans les tampons (voir man "
 "strftime pour le format de date/heure, des caractères de conversion "
 "supplémentaires sont supportés, voir la fonction util_strftimeval dans la "
 "Référence API extension) (note : le contenu est évalué, donc vous pouvez "
-"utiliser des couleurs avec le format \"${color:xxx}\", voir /help eval) ; "
-"par exemple l'heure avec des niveaux de gris : "
-"\"${color:252}%H${color:243}%M${color:237}%S\", le même format avec des "
-"millisecondes : \"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"utiliser des couleurs avec le format \"${color:xxx}\", voir /help eval) ; la "
+"variable \"${highlight}\" peut être utilisée dans une condition pour avoir "
+"un format spécifique aux lignes avec highlight ; par exemple l'heure avec "
+"des niveaux de gris : \"${color:252}%H${color:243}%M${color:237}%S\", le "
+"même format avec des millisecondes : "
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", fond rouge in cas de "
+"highlight : \"${if:${highlight}?${color:,red}}%H:%M:%S\", fond rouge en cas "
+"de highlight avec des niveaux de gris : \"${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S:"
+"${color:252}%H${color:243}%M${color:237}%S}\""
 
 #. TRANSLATORS: string "${color:xxx}" must NOT be translated
 msgid ""
diff --git a/po/hu.po b/po/hu.po
index 34094938c..569380480 100644
--- a/po/hu.po
+++ b/po/hu.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2023-11-29 09:59+0100\n"
 "Last-Translator: Andras Voroskoi <voroskoi@frugalware.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4081,10 +4081,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr "új nap kezdetével megjelenő időbélyeg"
 
 #. TRANSLATORS: string "${color:xxx}" must NOT be translated
diff --git a/po/it.po b/po/it.po
index 59be0d775..683441f79 100644
--- a/po/it.po
+++ b/po/it.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:32+0100\n"
 "Last-Translator: Esteban I. Ruiz Moreno <exio4.com@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4310,10 +4310,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "formato dell'ora per ogni riga visualizzata nei buffer (consultare man "
 "strftime per gli specificatori data/ora), i colori sono consentiti nel "
diff --git a/po/ja.po b/po/ja.po
index e11aa769a..579b68cd2 100644
--- a/po/ja.po
+++ b/po/ja.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:32+0100\n"
 "Last-Translator: AYANOKOUZI, Ryuunosuke <i38w7i3@yahoo.co.jp>\n"
 "Language-Team: Japanese <https://github.com/l/weechat/tree/master/"
@@ -4454,10 +4454,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "バッファに表示される行に付く時間書式 (日付/時間の指定子は strftime の man を"
 "参照してください) (注意: 値は評価されるため \"${color:xxx}\" 書式で色を指定出"
diff --git a/po/pl.po b/po/pl.po
index c53cc2a9f..3247fba35 100644
--- a/po/pl.po
+++ b/po/pl.po
@@ -22,7 +22,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:32+0100\n"
 "Last-Translator: Krzysztof Korościk <soltys@soltys.info>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4546,14 +4546,28 @@ msgstr ""
 "i wiadomości"
 
 #. TRANSLATORS: string "${color:xxx}" must NOT be translated
+#, fuzzy
+#| msgid ""
+#| "time format for each line displayed in buffers (see man strftime for date/"
+#| "time specifiers, extra specifiers are supported, see function "
+#| "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
+#| "you can use colors with format \"${color:xxx}\", see /help eval); for "
+#| "example time using grayscale: "
+#| "\"${color:252}%H${color:243}%M${color:237}%S\", the same with "
+#| "milliseconds: \"${color:252}%H${color:243}%M${color:237}%S.%.3\""
 msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "format czasu używany dla każdej linii w buforach (zobacz man strftime dla "
 "specyfikatorów daty/czasu, dodatkowe specyfikatory są wspierane, zobacz "
diff --git a/po/pt.po b/po/pt.po
index 1aab66d8b..3d67a63d2 100644
--- a/po/pt.po
+++ b/po/pt.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:32+0100\n"
 "Last-Translator: Vasco Almeida <vascomalmeida@sapo.pt>\n"
 "Language-Team: Portuguese <>\n"
@@ -4467,10 +4467,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "formato de data/hora de cada linha mostrada no buffer (ver man strftime para "
 "especificadores de data/hora) (nota: o conteúdo é avaliado, por isso pode "
diff --git a/po/pt_BR.po b/po/pt_BR.po
index 9936a7be0..3c506adec 100644
--- a/po/pt_BR.po
+++ b/po/pt_BR.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-02-17 10:07+0100\n"
 "Last-Translator: Érico Nogueira <ericonr@disroot.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4336,10 +4336,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "formato de tempo para cada linha mostrada nos buffers (veja man strftime "
 "para especificadores de data/tempo) (nota: o conteúdo é avaliado, então voce "
diff --git a/po/ru.po b/po/ru.po
index 4b7a8c88a..1c1a021a3 100644
--- a/po/ru.po
+++ b/po/ru.po
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2023-11-29 09:59+0100\n"
 "Last-Translator: Aleksey V Zapparov AKA ixti <ixti@member.fsf.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4106,10 +4106,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr "отображение маркера даты при смене дня"
 
 #. TRANSLATORS: string "${color:xxx}" must NOT be translated
diff --git a/po/sr.po b/po/sr.po
index dca55b901..f8131ce0e 100644
--- a/po/sr.po
+++ b/po/sr.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:32+0100\n"
 "Last-Translator: Ivan Pešić <ivan.pesic@gmail.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4560,14 +4560,28 @@ msgstr ""
 "подразумевана претрага текста у баферу: у поруци, префиксу, префиксу и поруци"
 
 #. TRANSLATORS: string "${color:xxx}" must NOT be translated
+#, fuzzy
+#| msgid ""
+#| "time format for each line displayed in buffers (see man strftime for date/"
+#| "time specifiers, extra specifiers are supported, see function "
+#| "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
+#| "you can use colors with format \"${color:xxx}\", see /help eval); for "
+#| "example time using grayscale: "
+#| "\"${color:252}%H${color:243}%M${color:237}%S\", the same with "
+#| "milliseconds: \"${color:252}%H${color:243}%M${color:237}%S.%.3\""
 msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "формат времена за сваку линију која се приказује у баферима (погледајте man "
 "strftime за спецификаторе датума/времена, подржани су додатни спецификатори, "
diff --git a/po/tr.po b/po/tr.po
index 18393b38f..7a53f6e18 100644
--- a/po/tr.po
+++ b/po/tr.po
@@ -20,7 +20,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2024-03-06 20:33+0100\n"
 "Last-Translator: Emir SARI <emir_sari@icloud.com>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -4482,10 +4482,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 "arabelleklerde görüntülenen her satır için zaman biçimi (tarih/zaman "
 "belirticileri için man strftime yapın) (not: içerik değerlendirilir, böylece "
diff --git a/po/weechat.pot b/po/weechat.pot
index e09102ed5..4d0669ed5 100644
--- a/po/weechat.pot
+++ b/po/weechat.pot
@@ -21,7 +21,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: WeeChat\n"
 "Report-Msgid-Bugs-To: flashcode@flashtux.org\n"
-"POT-Creation-Date: 2024-03-15 19:13+0100\n"
+"POT-Creation-Date: 2024-03-16 09:38+0100\n"
 "PO-Revision-Date: 2014-08-16 10:27+0200\n"
 "Last-Translator: Sébastien Helleu <flashcode@flashtux.org>\n"
 "Language-Team: weechat-dev <weechat-dev@nongnu.org>\n"
@@ -3830,10 +3830,15 @@ msgid ""
 "time format for each line displayed in buffers (see man strftime for date/"
 "time specifiers, extra specifiers are supported, see function "
 "util_strftimeval in Plugin API reference) (note: content is evaluated, so "
-"you can use colors with format \"${color:xxx}\", see /help eval); for "
-"example time using grayscale: "
+"you can use colors with format \"${color:xxx}\", see /help eval); variable "
+"\"${highlight}\" can be used in a condition to have a format specific to "
+"lines with highlight; for example time using grayscale: "
 "\"${color:252}%H${color:243}%M${color:237}%S\", the same with milliseconds: "
-"\"${color:252}%H${color:243}%M${color:237}%S.%.3\""
+"\"${color:252}%H${color:243}%M${color:237}%S.%.3\", red background in case "
+"of highlight: \"${if:${highlight}?${color:,red}}%H:%M:%S\", red background "
+"in case of highlight with grayscale: ${if:${highlight}?${color:"
+"yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+"${color:252}%H${color:243}%M${color:237}%S.%.3}"
 msgstr ""
 
 #. TRANSLATORS: string "${color:xxx}" must NOT be translated
diff --git a/src/core/core-config.c b/src/core/core-config.c
index 0a0b07845..34ef55851 100644
--- a/src/core/core-config.c
+++ b/src/core/core-config.c
@@ -3321,11 +3321,18 @@ config_weechat_init_options ()
                "strftime for date/time specifiers, extra specifiers are "
                "supported, see function util_strftimeval in Plugin API reference) "
                "(note: content is evaluated, so you can use colors with format "
-               "\"${color:xxx}\", see /help eval); "
+               "\"${color:xxx}\", see /help eval); variable \"${highlight}\" "
+               "can be used in a condition to have a format specific to lines "
+               "with highlight; "
                "for example time using grayscale: "
                "\"${color:252}%H${color:243}%M${color:237}%S\", "
                "the same with milliseconds: "
-               "\"${color:252}%H${color:243}%M${color:237}%S.%.3\""),
+               "\"${color:252}%H${color:243}%M${color:237}%S.%.3\", "
+               "red background in case of highlight: "
+               "\"${if:${highlight}?${color:,red}}%H:%M:%S\", "
+               "red background in case of highlight with grayscale: "
+               "${if:${highlight}?${color:yellow,124}%H${color:187}%M${color:181}%S.%.3:"
+               "${color:252}%H${color:243}%M${color:237}%S.%.3}"),
             NULL, 0, 0, "%H:%M:%S", NULL, 0,
             NULL, NULL, NULL,
             &config_change_buffer_time_format, NULL, NULL,
diff --git a/src/gui/gui-chat.c b/src/gui/gui-chat.c
index a1ff81322..53d029b27 100644
--- a/src/gui/gui-chat.c
+++ b/src/gui/gui-chat.c
@@ -390,12 +390,13 @@ gui_chat_get_word_info (struct t_gui_window *window,
  */
 
 char *
-gui_chat_get_time_string (time_t date, int date_usec)
+gui_chat_get_time_string (time_t date, int date_usec, int highlight)
 {
     char text_time[128], text_time2[(128*3)+16], text_time_char[2];
     char *text_with_color;
     int i, time_first_digit, time_last_digit, last_color;
     struct timeval tv;
+    struct t_hashtable *extra_vars;
 
     if (date == 0)
         return NULL;
@@ -413,7 +414,15 @@ gui_chat_get_time_string (time_t date, int date_usec)
 
     if (strstr (text_time, "${"))
     {
-        text_with_color = eval_expression (text_time, NULL, NULL, NULL);
+        extra_vars = hashtable_new (32,
+                                    WEECHAT_HASHTABLE_STRING,
+                                    WEECHAT_HASHTABLE_STRING,
+                                    NULL, NULL);
+        if (extra_vars)
+            hashtable_set (extra_vars, "highlight", (highlight) ? "1" : "0");
+        text_with_color = eval_expression (text_time, NULL, extra_vars, NULL);
+        if (extra_vars)
+            hashtable_free (extra_vars);
         if (text_with_color)
         {
             if (strcmp (text_time, text_with_color) != 0)
@@ -510,7 +519,7 @@ gui_chat_get_time_length ()
 
     length = 0;
     gettimeofday (&tv_now, NULL);
-    text_time = gui_chat_get_time_string (tv_now.tv_sec, tv_now.tv_usec);
+    text_time = gui_chat_get_time_string (tv_now.tv_sec, tv_now.tv_usec, 0);
 
     if (text_time)
     {
@@ -543,7 +552,8 @@ gui_chat_change_time_format ()
                     free (ptr_line->data->str_time);
                 ptr_line->data->str_time = gui_chat_get_time_string (
                     ptr_line->data->date,
-                    ptr_line->data->date_usec);
+                    ptr_line->data->date_usec,
+                    ptr_line->data->highlight);
             }
         }
     }
diff --git a/src/gui/gui-chat.h b/src/gui/gui-chat.h
index 18a3b9bba..3ef59f587 100644
--- a/src/gui/gui-chat.h
+++ b/src/gui/gui-chat.h
@@ -90,7 +90,8 @@ extern void gui_chat_get_word_info (struct t_gui_window *window,
                                     int *word_end_offset,
                                     int *word_length_with_spaces,
                                     int *word_length);
-extern char *gui_chat_get_time_string (time_t date, int date_usec);
+extern char *gui_chat_get_time_string (time_t date, int date_usec,
+                                       int highlight);
 extern int gui_chat_get_time_length ();
 extern void gui_chat_change_time_format ();
 extern int gui_chat_buffer_valid (struct t_gui_buffer *buffer,
diff --git a/src/gui/gui-line.c b/src/gui/gui-line.c
index 43eb68baa..bfdd2f1d8 100644
--- a/src/gui/gui-line.c
+++ b/src/gui/gui-line.c
@@ -1528,7 +1528,6 @@ gui_line_new (struct t_gui_buffer *buffer, int y,
         new_line->data->date_usec = date_usec;
         new_line->data->date_printed = date_printed;
         new_line->data->date_usec_printed = date_usec_printed;
-        new_line->data->str_time = gui_chat_get_time_string (date, date_usec);
         gui_line_tags_alloc (new_line->data, tags);
         new_line->data->refresh_needed = 0;
         new_line->data->prefix = (prefix) ?
@@ -1540,6 +1539,8 @@ gui_line_new (struct t_gui_buffer *buffer, int y,
         gui_line_set_highlight (new_line, max_notify_level);
         if (new_line->data->highlight && (new_line->data->notify_level >= 0))
             new_line->data->notify_level = GUI_HOTLIST_HIGHLIGHT;
+        new_line->data->str_time = gui_chat_get_time_string (
+            date, date_usec, new_line->data->highlight);
     }
     else
     {
@@ -1642,6 +1643,30 @@ gui_line_hook_update (struct t_gui_line *line,
         }
     }
 
+    ptr_value2 = hashtable_get (hashtable2, "notify_level");
+    if (ptr_value2)
+    {
+        error = NULL;
+        value = strtol (ptr_value2, &error, 10);
+        if (error && !error[0] && (value >= -1) && (value <= GUI_HOTLIST_MAX))
+        {
+            notify_level_updated = 1;
+            line->data->notify_level = value;
+        }
+    }
+
+    ptr_value2 = hashtable_get (hashtable2, "highlight");
+    if (ptr_value2)
+    {
+        error = NULL;
+        value = strtol (ptr_value2, &error, 10);
+        if (error && !error[0])
+        {
+            highlight_updated = 1;
+            line->data->highlight = (value) ? 1 : 0;
+        }
+    }
+
     ptr_value2 = hashtable_get (hashtable2, "date");
     if (ptr_value2)
     {
@@ -1654,7 +1679,8 @@ gui_line_hook_update (struct t_gui_line *line,
                 free (line->data->str_time);
             line->data->str_time = gui_chat_get_time_string (
                 line->data->date,
-                line->data->date_usec);
+                line->data->date_usec,
+                line->data->highlight);
         }
     }
 
@@ -1670,7 +1696,8 @@ gui_line_hook_update (struct t_gui_line *line,
                 free (line->data->str_time);
             line->data->str_time = gui_chat_get_time_string (
                 line->data->date,
-                line->data->date_usec);
+                line->data->date_usec,
+                line->data->highlight);
         }
     }
 
@@ -1710,30 +1737,6 @@ gui_line_hook_update (struct t_gui_line *line,
         gui_line_tags_alloc (line->data, ptr_value2);
     }
 
-    ptr_value2 = hashtable_get (hashtable2, "notify_level");
-    if (ptr_value2)
-    {
-        error = NULL;
-        value = strtol (ptr_value2, &error, 10);
-        if (error && !error[0] && (value >= -1) && (value <= GUI_HOTLIST_MAX))
-        {
-            notify_level_updated = 1;
-            line->data->notify_level = value;
-        }
-    }
-
-    ptr_value2 = hashtable_get (hashtable2, "highlight");
-    if (ptr_value2)
-    {
-        error = NULL;
-        value = strtol (ptr_value2, &error, 10);
-        if (error && !error[0])
-        {
-            highlight_updated = 1;
-            line->data->highlight = (value) ? 1 : 0;
-        }
-    }
-
     ptr_value = hashtable_get (hashtable, "prefix");
     ptr_value2 = hashtable_get (hashtable2, "prefix");
     if (ptr_value2 && (!ptr_value || (strcmp (ptr_value, ptr_value2) != 0)))
@@ -2218,7 +2221,8 @@ gui_line_hdata_line_data_update_cb (void *data,
                 free (line_data->str_time);
             line_data->str_time = gui_chat_get_time_string (
                 line_data->date,
-                line_data->date_usec);
+                line_data->date_usec,
+                line_data->highlight);
             rc++;
             update_coords = 1;
         }
@@ -2234,7 +2238,8 @@ gui_line_hdata_line_data_update_cb (void *data,
                 free (line_data->str_time);
             line_data->str_time = gui_chat_get_time_string (
                 line_data->date,
-                line_data->date_usec);
+                line_data->date_usec,
+                line_data->highlight);
             rc++;
             update_coords = 1;
         }
diff --git a/tests/unit/gui/test-gui-line.cpp b/tests/unit/gui/test-gui-line.cpp
index 02a0beaee..bc3aa1c64 100644
--- a/tests/unit/gui/test-gui-line.cpp
+++ b/tests/unit/gui/test-gui-line.cpp
@@ -854,7 +854,7 @@ TEST(GuiLine, New)
     gettimeofday (&date_printed, NULL);
     date.tv_sec = date_printed.tv_sec - 1;
     date.tv_usec = date_printed.tv_usec;
-    str_time = gui_chat_get_time_string (date.tv_sec, date.tv_usec);
+    str_time = gui_chat_get_time_string (date.tv_sec, date.tv_usec, 0);
 
     POINTERS_EQUAL(NULL,
                    gui_line_new (