diff --git a/src/public/app/services/utils.js b/src/public/app/services/utils.js
index b88146012..99871035a 100644
--- a/src/public/app/services/utils.js
+++ b/src/public/app/services/utils.js
@@ -73,8 +73,34 @@ function formatDateISO(date) {
     return `${date.getFullYear()}-${padNum(date.getMonth() + 1)}-${padNum(date.getDate())}`;
 }
 
-function formatDateTime(date) {
-    return `${formatDate(date)} ${formatTime(date)}`;
+// old version
+// function formatDateTime(date) {
+//     return `${formatDate(date)} ${formatTime(date)}`;
+// }
+
+// In utils.js
+// import dayjs from 'dayjs'; // Assuming dayjs is available in this scope
+
+// new version
+function formatDateTime(date, userSuppliedFormat) {
+    let formatToUse;
+
+    if (userSuppliedFormat && typeof userSuppliedFormat === 'string' && userSuppliedFormat.trim() !== "") {
+        formatToUse = userSuppliedFormat.trim();
+    } else {
+        formatToUse = 'YYYY-MM-DD HH:mm'; // Trilium's default format
+    }
+
+    if (!date) {
+        date = new Date();
+    }
+
+    try {
+        return dayjs(date).format(formatToUse);
+    } catch (e) {
+        console.warn(`Day.js: Invalid format string "${formatToUse}". Falling back. Error:`, e.message);
+        return dayjs(date).format('YYYY-MM-DD HH:mm');
+    }
 }
 
 function localNowDateTime() {
diff --git a/src/public/app/widgets/type_widgets/content_widget.js b/src/public/app/widgets/type_widgets/content_widget.js
index fe7f105af..aaa33470f 100644
--- a/src/public/app/widgets/type_widgets/content_widget.js
+++ b/src/public/app/widgets/type_widgets/content_widget.js
@@ -8,6 +8,7 @@ import KeyboardShortcutsOptions from "./options/shortcuts.js";
 import HeadingStyleOptions from "./options/text_notes/heading_style.js";
 import TableOfContentsOptions from "./options/text_notes/table_of_contents.js";
 import HighlightsListOptions from "./options/text_notes/highlights_list.js";
+import DateTimeFormatOptions from "./options/text_notes/date_time_format.js";
 import TextAutoReadOnlySizeOptions from "./options/text_notes/text_auto_read_only_size.js";
 import VimKeyBindingsOptions from "./options/code_notes/vim_key_bindings.js";
 import WrapLinesOptions from "./options/code_notes/wrap_lines.js";
@@ -66,6 +67,7 @@ const CONTENT_WIDGETS = {
         HeadingStyleOptions,
         TableOfContentsOptions,
         HighlightsListOptions,
+        DateTimeFormatOptions,
         TextAutoReadOnlySizeOptions
     ],
     _optionsCodeNotes: [
diff --git a/src/public/app/widgets/type_widgets/editable_text.js b/src/public/app/widgets/type_widgets/editable_text.js
index 48cb041aa..897add401 100644
--- a/src/public/app/widgets/type_widgets/editable_text.js
+++ b/src/public/app/widgets/type_widgets/editable_text.js
@@ -9,6 +9,7 @@ import AbstractTextTypeWidget from "./abstract_text_type_widget.js";
 import link from "../../services/link.js";
 import appContext from "../../components/app_context.js";
 import dialogService from "../../services/dialog.js";
+import server from '../../services/server.js';
 
 const ENABLE_INSPECTOR = false;
 
@@ -109,9 +110,9 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
             (await mimeTypesService.getMimeTypes())
                 .filter(mt => mt.enabled)
                 .map(mt => ({
-                        language: mt.mime.toLowerCase().replace(/[\W_]+/g,"-"),
-                        label: mt.title
-                    }));
+                    language: mt.mime.toLowerCase().replace(/[\W_]+/g, "-"),
+                    label: mt.title
+                }));
 
         // CKEditor since version 12 needs the element to be visible before initialization. At the same time,
         // we want to avoid flicker - i.e., show editor only once everything is ready. That's why we have separate
@@ -211,7 +212,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         this.watchdog?.editor.editing.view.focus();
     }
 
-    show() {}
+    show() { }
 
     getEditor() {
         return this.watchdog?.editor;
@@ -225,10 +226,29 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         }
     }
 
-    insertDateTimeToTextCommand() {
-        const date = new Date();
-        const dateString = utils.formatDateTime(date);
+    // old version
+    // insertDateTimeToTextCommand() {
+    //     const date = new Date();
+    //     const dateString = utils.formatDateTime(date);
 
+    //     this.addTextToEditor(dateString);
+    // }
+
+    // new version
+    async insertDateTimeToTextCommand() {
+        const date = new Date();
+        let userPreferredFormat = ""; //Default
+
+        try {
+            const allOptions = await server.get('options');
+            
+            if (allOptions && typeof allOptions.customDateTimeFormatString === 'string') {
+                userPreferredFormat = allOptions.customDateTimeFormatString;
+            }
+        } catch (e) {
+            console.error("Trilium: Failed to fetch options for custom date/time format. Using default.", e);
+        }
+        const dateString = utils.formatDateTime(date, userPreferredFormat);
         this.addTextToEditor(dateString);
     }
 
@@ -237,7 +257,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
 
         this.watchdog.editor.model.change(writer => {
             const insertPosition = this.watchdog.editor.model.document.selection.getFirstPosition();
-            writer.insertText(linkTitle, {linkHref: linkHref}, insertPosition);
+            writer.insertText(linkTitle, { linkHref: linkHref }, insertPosition);
         });
     }
 
@@ -250,7 +270,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         });
     }
 
-    addTextToActiveEditorEvent({text}) {
+    addTextToActiveEditorEvent({ text }) {
         if (!this.isActive()) {
             return;
         }
@@ -283,7 +303,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         return !selection.isCollapsed;
     }
 
-    async executeWithTextEditorEvent({callback, resolve, ntxId}) {
+    async executeWithTextEditorEvent({ callback, resolve, ntxId }) {
         if (!this.isNoteContext(ntxId)) {
             return;
         }
@@ -300,7 +320,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
     addLinkToTextCommand() {
         const selectedText = this.getSelectedText();
 
-        this.triggerCommand('showAddLinkDialog', {textTypeWidget: this, text: selectedText})
+        this.triggerCommand('showAddLinkDialog', { textTypeWidget: this, text: selectedText })
     }
 
     getSelectedText() {
@@ -347,29 +367,29 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
     }
 
     addIncludeNoteToTextCommand() {
-        this.triggerCommand("showIncludeNoteDialog", {textTypeWidget: this});
+        this.triggerCommand("showIncludeNoteDialog", { textTypeWidget: this });
     }
 
     addIncludeNote(noteId, boxSize) {
-        this.watchdog.editor.model.change( writer => {
+        this.watchdog.editor.model.change(writer => {
             // Insert <includeNote>*</includeNote> at the current selection position
             // in a way that will result in creating a valid model structure
             this.watchdog.editor.model.insertContent(writer.createElement('includeNote', {
                 noteId: noteId,
                 boxSize: boxSize
             }));
-        } );
+        });
     }
 
     async addImage(noteId) {
         const note = await froca.getNote(noteId);
 
-        this.watchdog.editor.model.change( writer => {
+        this.watchdog.editor.model.change(writer => {
             const encodedTitle = encodeURIComponent(note.title);
             const src = `api/images/${note.noteId}/${encodedTitle}`;
 
-            this.watchdog.editor.execute( 'insertImage', { source: src } );
-        } );
+            this.watchdog.editor.execute('insertImage', { source: src });
+        });
     }
 
     async createNoteForReferenceLink(title) {
@@ -385,7 +405,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         return resp.note.getBestNotePathString();
     }
 
-    async refreshIncludedNoteEvent({noteId}) {
+    async refreshIncludedNoteEvent({ noteId }) {
         this.refreshIncludedNote(this.$editor, noteId);
     }
 }
diff --git a/src/public/app/widgets/type_widgets/options/text_notes/date_time_format.js b/src/public/app/widgets/type_widgets/options/text_notes/date_time_format.js
new file mode 100644
index 000000000..7eb5916c3
--- /dev/null
+++ b/src/public/app/widgets/type_widgets/options/text_notes/date_time_format.js
@@ -0,0 +1,75 @@
+import OptionsWidget from "../options_widget.js";
+
+const TPL = `
+<div class="options-section">
+    <h4>Custom Date/Time Format (Alt+T)</h4>
+
+    <p>
+        Define a custom format for the date and time inserted using the Alt+T shortcut.
+        Uses <a href="https://day.js.org/docs/en/display/format" target="_blank" rel="noopener noreferrer">Day.js format tokens</a>.
+        Refer to the Day.js documentation for valid tokens.
+    </p>
+<p>
+    <strong>Important:</strong> If you provide a format string that Day.js does not recognize
+    (e.g., mostly plain text without valid <a href="https://day.js.org/docs/en/display/format" target="_blank" rel="noopener noreferrer">Day.js tokens</a>),
+    the text you typed might be inserted literally. If the format string is left empty,
+    or if Day.js encounters a critical internal error with your format,
+    a default format (e.g., YYYY-MM-DD HH:mm) will be used.
+</p>
+
+    <div class="form-group">
+        <label for="customDateTimeFormatInput" style="margin-right: 10px;">Format String:</label>
+        <input type="text" id="customDateTimeFormatInput" class="form-control custom-datetime-format-input" placeholder="e.g., DD/MM/YYYY HH:mm:ss or dddd, MMMM D" style="width: 300px; display: inline-block;">
+    </div>
+    <p style="margin-top: 5px;">
+        <em>Examples of valid Day.js formats:</em>
+        <code>YYYY-MM-DD HH:mm</code> (Default-like),
+        <code>DD.MM.YYYY</code>,
+        <code>MMMM D, YYYY h:mm A</code>,
+        <code>[Today is] dddd</code>
+    </p>
+</div>
+`;
+
+export default class DateTimeFormatOptions extends OptionsWidget {
+    doRender() {
+        this.$widget = $(TPL);
+        this.$formatInput = this.$widget.find(
+            "input.custom-datetime-format-input"
+        );
+
+        //listen to input
+        this.$formatInput.on("input", () => {
+            const formatString = this.$formatInput.val();
+
+            this.updateOption("customDateTimeFormatString", formatString);
+        });
+
+        return this.$widget; //render method to return the widget
+    }
+
+    async optionsLoaded(options) {
+        const currentFormat = options.customDateTimeFormatString || "";
+
+
+        if (this.$formatInput) {
+            this.$formatInput.val(currentFormat);
+        } else {
+
+            console.warn(
+                "DateTimeFormatOptions: $formatInput not initialized when optionsLoaded was called. Attempting to find again."
+            );
+            const inputField = this.$widget.find(
+                "input.custom-datetime-format-input"
+            );
+            if (inputField.length) {
+                this.$formatInput = inputField;
+                this.$formatInput.val(currentFormat);
+            } else {
+                console.error(
+                    "DateTimeFormatOptions: Could not find format input field in optionsLoaded."
+                );
+            }
+        }
+    }
+}
diff --git a/src/routes/api/options.js b/src/routes/api/options.js
index efd70a07e..5f317945b 100644
--- a/src/routes/api/options.js
+++ b/src/routes/api/options.js
@@ -57,7 +57,8 @@ const ALLOWED_OPTIONS = new Set([
     'customSearchEngineName',
     'customSearchEngineUrl',
     'promotedAttributesOpenInRibbon',
-    'editedNotesOpenInRibbon'
+    'editedNotesOpenInRibbon',
+    'customDateTimeFormatString'
 ]);
 
 function getOptions() {