diff --git a/CHANGELOG.md b/CHANGELOG.md
index 59b52e7145..9a170d3316 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,10 +12,12 @@ _This release is scheduled to be released on 2024-01-01._
 ### Added
 
 - Added node 21 to the test matrix
+- Added transform object to calendar:customEvents
 
 ### Removed
 
 - Removed Codecov workflow (not working anymore, other workflow required) (#3107)
+- Removed titleReplace from calendar, replaced + extended by customEvents (backward compatibility included)
 
 ### Updated
 
diff --git a/modules/default/calendar/calendar.js b/modules/default/calendar/calendar.js
index c923ee50de..287a424a73 100644
--- a/modules/default/calendar/calendar.js
+++ b/modules/default/calendar/calendar.js
@@ -155,6 +155,14 @@ Module.register("calendar", {
 			this.addCalendar(calendar.url, calendar.auth, calendarConfig);
 		});
 
+		// for backward compatibility titleReplace
+		if (typeof this.config.titleReplace !== "undefined") {
+			Log.warn("Deprecation warning: Please consider upgrading your calendar titleReplace configuration to customEvents.");
+			for (const [titlesearchstr, titlereplacestr] of Object.entries(this.config.titleReplace)) {
+				this.config.customEvents.push({ keyword: ".*", transform: { search: titlesearchstr, replace: titlereplacestr } });
+			}
+		}
+
 		this.selfUpdate();
 	},
 
@@ -326,11 +334,16 @@ Module.register("calendar", {
 				}
 			}
 
-			// Color events if custom color or eventClass are specified
+			var transformedTitle = event.title;
+
+			// Color events if custom color or eventClass are specified, transform title if required
 			if (this.config.customEvents.length > 0) {
 				for (let ev in this.config.customEvents) {
 					let needle = new RegExp(this.config.customEvents[ev].keyword, "gi");
 					if (needle.test(event.title)) {
+						if (typeof this.config.customEvents[ev].transform === "object") {
+							transformedTitle = CalendarUtils.titleTransform(transformedTitle, [this.config.customEvents[ev].transform]);
+						}
 						if (typeof this.config.customEvents[ev].color !== "undefined" && this.config.customEvents[ev].color !== "") {
 							// Respect parameter ColoredSymbolOnly also for custom events
 							if (this.config.coloredText) {
@@ -348,7 +361,6 @@ Module.register("calendar", {
 				}
 			}
 
-			const transformedTitle = CalendarUtils.titleTransform(event.title, this.config.titleReplace);
 			titleWrapper.innerHTML = CalendarUtils.shorten(transformedTitle, this.config.maxTitleLength, this.config.wrapEvents, this.config.maxTitleLines) + repeatingCountTitle;
 
 			const titleClass = this.titleClassForUrl(event.url);
diff --git a/modules/default/calendar/calendarutils.js b/modules/default/calendar/calendarutils.js
index e953b6352c..1bfdf15992 100644
--- a/modules/default/calendar/calendarutils.js
+++ b/modules/default/calendar/calendarutils.js
@@ -90,23 +90,39 @@ const CalendarUtils = {
 	/**
 	 * Transforms the title of an event for usage.
 	 * Replaces parts of the text as defined in config.titleReplace.
-	 * Shortens title based on config.maxTitleLength and config.wrapEvents
 	 * @param {string} title The title to transform.
-	 * @param {object} titleReplace Pairs of strings to be replaced in the title
+	 * @param {object} titleReplace object definition of parts to be replaced in the title
+	 *                 object definition:
+	 *                    search: {string,required} RegEx in format //x or simple string to be searched. For (birthday) year calcluation, the element matching the year must be in a RegEx group
+	 *                    replace: {string,required} Replacement string, may contain match group references (latter is required for year calculation)
+	 *                    yearmatchgroup: {number,optional} match group for year element
 	 * @returns {string} The transformed title.
 	 */
 	titleTransform: function (title, titleReplace) {
 		let transformedTitle = title;
-		for (let needle in titleReplace) {
-			const replacement = titleReplace[needle];
+		for (let tr in titleReplace) {
+			let transform = titleReplace[tr];
+			if (typeof transform === "object") {
+				if (typeof transform.search !== "undefined" && transform.search !== "" && typeof transform.replace !== "undefined") {
+					let regParts = transform.search.match(/^\/(.+)\/([gim]*)$/);
+					let needle = new RegExp(transform.search, "g");
+					if (regParts) {
+						// the parsed pattern is a regexp with flags.
+						needle = new RegExp(regParts[1], regParts[2]);
+					}
 
-			const regParts = needle.match(/^\/(.+)\/([gim]*)$/);
-			if (regParts) {
-				// the parsed pattern is a regexp.
-				needle = new RegExp(regParts[1], regParts[2]);
+					let replacement = transform.replace;
+					if (typeof transform.yearmatchgroup !== "undefined" && transform.yearmatchgroup !== "") {
+						const yearmatch = [...title.matchAll(needle)];
+						if (yearmatch[0].length >= transform.yearmatchgroup + 1 && yearmatch[0][transform.yearmatchgroup] * 1 >= 1900) {
+							let calcage = new Date().getFullYear() - yearmatch[0][transform.yearmatchgroup] * 1;
+							let searchstr = `$${transform.yearmatchgroup}`;
+							replacement = replacement.replace(searchstr, calcage);
+						}
+					}
+					transformedTitle = transformedTitle.replace(needle, replacement);
+				}
 			}
-
-			transformedTitle = transformedTitle.replace(needle, replacement);
 		}
 		return transformedTitle;
 	}
diff --git a/tests/unit/modules/default/calendar/calendar_utils_spec.js b/tests/unit/modules/default/calendar/calendar_utils_spec.js
index 7cf896c137..ff37299fe9 100644
--- a/tests/unit/modules/default/calendar/calendar_utils_spec.js
+++ b/tests/unit/modules/default/calendar/calendar_utils_spec.js
@@ -138,11 +138,16 @@ describe("Calendar utils tests", () => {
 
 	describe("titleTransform and shorten combined", () => {
 		it("should replace the birthday and wrap nicely", () => {
-			const transformedTitle = CalendarUtils.titleTransform("Michael Teeuw's birthday", {
-				"De verjaardag van ": "",
-				"'s birthday": ""
-			});
+			const transformedTitle = CalendarUtils.titleTransform("Michael Teeuw's birthday", [{ search: "'s birthday", replace: "" }]);
 			expect(CalendarUtils.shorten(transformedTitle, 10, true, 2)).toBe("Michael <br>Teeuw");
 		});
 	});
+
+	describe("titleTransform with yearmatchgroup", () => {
+		it("should replace the birthday and wrap nicely", () => {
+			const transformedTitle = CalendarUtils.titleTransform("Luciella '2000", [{ search: "^([^']*) '(\\d{4})$", replace: "$1 ($2.)", yearmatchgroup: 2 }]);
+			const expectedResult = `Luciella (${new Date().getFullYear() - 2000}.)`;
+			expect(transformedTitle).toBe(expectedResult);
+		});
+	});
 });