diff --git a/packages/message-parser/src/grammar.pegjs b/packages/message-parser/src/grammar.pegjs
index e69fcd86f4efe..0173a2e089eea 100644
--- a/packages/message-parser/src/grammar.pegjs
+++ b/packages/message-parser/src/grammar.pegjs
@@ -33,6 +33,7 @@
     tasks,
     unorderedList,
     timestamp,
+    timestampFromHours,
   } = require('./utils');
 
 let skipBold = false;
@@ -74,12 +75,28 @@ Blockquote = b:BlockquoteLine+ { return quote(b); }
 BlockquoteLine = ">" [ \t]* @Paragraph
 
 // <t:1630360800:?{format}>
+// <t:2025-07-22T10:00:00.000Z?:?{format}>
+// <t:2025-07-22T10:00:00:?{format}>
+// <t:00:00:?{format}>
 
 TimestampType = "t" / "T" / "d" / "D" / "f" / "F" / "R"
 
 Unixtime = d:Digit |10| { return d.join(''); }
 
-Timestamp = "<t:" date:Unixtime ":" format:TimestampType ">" { return timestamp(date, format); } / "<t:" date:Unixtime ">" { return timestamp(date); }
+TimestampHoursMinutesSeconds = hours:Digit |2| ":" minutes:Digit|2| ":" seconds:Digit |2| "Z"? { return timestampFromHours(hours.join(''), minutes.join(''), seconds.join('')); }
+
+TimestampHoursMinutes = hours:Digit |2| ":" minutes:Digit|2| "Z"? { return timestampFromHours(hours.join(''), minutes.join('')); }
+
+
+Timestamp = TimestampHoursMinutesSeconds / TimestampHoursMinutes
+
+
+ISO8601Date = year:Digit |4| "-" month:Digit |2| "-" day:Digit |2| "T" hours:Digit |2| ":" minutes:Digit|2| ":" seconds:Digit |2| "." milliseconds:Digit |3| "Z"? { return new Date(year.join('') + '-' + month.join('') + '-' + day.join('') + 'T' + hours.join('') + ':' + minutes.join('') + ':' + seconds.join('') + '.' + milliseconds.join('') + 'Z').getTime().toString(); }
+
+ISO8601DateWithoutMilliseconds = year:Digit |4| "-" month:Digit |2| "-" day:Digit |2| "T" hours:Digit |2| ":" minutes:Digit|2| ":" seconds:Digit |2| "Z"? { return new Date(year.join('') + '-' + month.join('') + '-' + day.join('') + 'T' + hours.join('') + ':' + minutes.join('') + ':' + seconds.join('') + 'Z').getTime().toString(); }
+
+
+TimestampRules = "<t:" date:(Unixtime / ISO8601Date / ISO8601DateWithoutMilliseconds / Timestamp) ":" format:TimestampType ">" { return timestamp(date, format); } / "<t:" date:(Unixtime / ISO8601Date / ISO8601DateWithoutMilliseconds / Timestamp) ">" { return timestamp(date); }
 
 /**
  *
@@ -230,7 +247,7 @@ InlineEmoji = & { return !skipInlineEmoji; } emo:Emoji { return emo; }
 InlineEmoticon = & { return !skipInlineEmoji; } emo:Emoticon & (EmoticonNeighbor / InlineItemPattern) { skipInlineEmoji = false; return emo; }
 
 InlineItemPattern = Whitespace
-  / Timestamp
+  / TimestampRules
   / MaybeReferences
   / AutolinkedPhone
   / AutolinkedEmail
@@ -494,7 +511,7 @@ BoldEmoticon = & { return !skipBoldEmoji; } emo:Emoticon & (EmoticonNeighbor / B
 /* Strike */
 Strikethrough = [\x7E] [\x7E] @StrikethroughContent [\x7E] [\x7E] / [\x7E] @StrikethroughContent [\x7E]
 
-StrikethroughContent = text:(Timestamp / Whitespace / InlineCode / MaybeReferences / UserMention / ChannelMention / MaybeItalic / MaybeBold / Emoji / Emoticon / AnyStrike / Line)+ {
+StrikethroughContent = text:(TimestampRules / Whitespace / InlineCode / MaybeReferences / UserMention / ChannelMention / MaybeItalic / MaybeBold / Emoji / Emoticon / AnyStrike / Line)+ {
       return strike(reducePlainTexts(text));
     }
 
diff --git a/packages/message-parser/src/utils.ts b/packages/message-parser/src/utils.ts
index 5a52fad9b887c..3bf9b8f689c80 100644
--- a/packages/message-parser/src/utils.ts
+++ b/packages/message-parser/src/utils.ts
@@ -251,6 +251,20 @@ export const timestamp = (
   };
 };
 
+export const timestampFromHours = (
+  hours: string,
+  minutes = '00',
+  seconds = '00',
+) => {
+  const date = new Date();
+
+  const yearMonthDay = date.toISOString().split('T')[0];
+
+  return new Date(`${yearMonthDay}T${hours}:${minutes}:${seconds}Z`)
+    .getTime()
+    .toString();
+};
+
 export const extractFirstResult = (
   value: Types[keyof Types]['value'],
 ): Types[keyof Types]['value'] => {
diff --git a/packages/message-parser/tests/timestamp.test.ts b/packages/message-parser/tests/timestamp.test.ts
index bb9b72655896e..1073125aacc2e 100644
--- a/packages/message-parser/tests/timestamp.test.ts
+++ b/packages/message-parser/tests/timestamp.test.ts
@@ -1,5 +1,12 @@
 import { parse } from '../src';
-import { bold, paragraph, plain, strike, timestamp } from '../src/utils';
+import {
+  bold,
+  paragraph,
+  plain,
+  strike,
+  timestamp,
+  timestampFromHours,
+} from '../src/utils';
 
 test.each([
   [`<t:1708551317>`, [paragraph([timestamp('1708551317')])]],
@@ -25,3 +32,37 @@ test.each([
 ])('parses %p', (input, output) => {
   expect(parse(input)).toMatchObject(output);
 });
+
+test.each([
+  [
+    '<t:2025-07-22T10:00:00.000Z:R>',
+    [paragraph([timestamp('1753178400000', 'R')])],
+  ],
+  [
+    '<t:2025-07-22T10:00:00.000Z:R>',
+    [paragraph([timestamp('1753178400000', 'R')])],
+  ],
+  [
+    '<t:2025-07-22T10:00:00.000:R>',
+    [paragraph([timestamp('1753178400000', 'R')])],
+  ],
+  ['<t:2025-07-22T10:00:00:R>', [paragraph([timestamp('1753178400000', 'R')])]],
+  [
+    '<t:10:00:00:R>',
+    [paragraph([timestamp(timestampFromHours('10', '00', '00'), 'R')])],
+  ],
+  [
+    '<t:10:00:R>',
+    [paragraph([timestamp(timestampFromHours('10', '00', '00'), 'R')])],
+  ],
+  [
+    '<t:10:00:00>',
+    [paragraph([timestamp(timestampFromHours('10', '00', '00'), 't')])],
+  ],
+  [
+    '<t:10:00>',
+    [paragraph([timestamp(timestampFromHours('10', '00', '00'), 't')])],
+  ],
+])('parses %p', (input, output) => {
+  expect(parse(input)).toMatchObject(output);
+});