diff --git a/apps/client/src/services/utils.ts b/apps/client/src/services/utils.ts
index a52b7443a..92ca2bc70 100644
--- a/apps/client/src/services/utils.ts
+++ b/apps/client/src/services/utils.ts
@@ -124,8 +124,31 @@ function formatDateISO(date: Date) {
     return `${date.getFullYear()}-${padNum(date.getMonth() + 1)}-${padNum(date.getDate())}`;
 }
 
-function formatDateTime(date: Date) {
-    return `${formatDate(date)} ${formatTime(date)}`;
+
+// old version
+// function formatDateTime(date: Date) {
+//     return `${formatDate(date)} ${formatTime(date)}`;
+// }
+
+// new version 
+export function formatDateTime(date: Date, userSuppliedFormat?: string): string { 
+    const DEFAULT_FORMAT = 'YYYY-MM-DD HH:mm'; 
+    let formatToUse = DEFAULT_FORMAT;
+
+    if (userSuppliedFormat && typeof userSuppliedFormat === 'string' && userSuppliedFormat.trim() !== "") {
+        formatToUse = userSuppliedFormat.trim();
+    }
+
+    if (!date) {
+        date = new Date(); 
+    }
+
+    try {
+        return dayjs(date).format(formatToUse);
+    } catch (e: any) {
+        console.warn(`TriliumNext: Day.js encountered an error with format string "${formatToUse}". Falling back to default. Error: ${e.message}`);
+        return dayjs(date).format(DEFAULT_FORMAT);
+    }
 }
 
 function localNowDateTime() {
diff --git a/apps/client/src/widgets/type_widgets/content_widget.ts b/apps/client/src/widgets/type_widgets/content_widget.ts
index 00c30f5f7..aa3eadcb0 100644
--- a/apps/client/src/widgets/type_widgets/content_widget.ts
+++ b/apps/client/src/widgets/type_widgets/content_widget.ts
@@ -45,6 +45,7 @@ import LanguageOptions from "./options/i18n/language.js";
 import type BasicWidget from "../basic_widget.js";
 import CodeTheme from "./options/code_notes/code_theme.js";
 import RelatedSettings from "./options/related_settings.js";
+import DateTimeFormatOptions from "./options/text_notes/date_time_format.js";
 
 const TPL = /*html*/`<div class="note-detail-content-widget note-detail-printable">
     <style>
@@ -83,6 +84,7 @@ const CONTENT_WIDGETS: Record<OptionPages | "_backendLog", (typeof NoteContextAw
         KeyboardShortcutsOptions
     ],
     _optionsTextNotes: [
+        DateTimeFormatOptions,
         EditorOptions,
         HeadingStyleOptions,
         CodeBlockOptions,
diff --git a/apps/client/src/widgets/type_widgets/editable_text.ts b/apps/client/src/widgets/type_widgets/editable_text.ts
index e1faac24f..4e530f990 100644
--- a/apps/client/src/widgets/type_widgets/editable_text.ts
+++ b/apps/client/src/widgets/type_widgets/editable_text.ts
@@ -267,7 +267,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
                         }
 
                         item.on("change:isOpen", () => {
-                            if (!("isOpen" in item) || !item.isOpen ) {
+                            if (!("isOpen" in item) || !item.isOpen) {
                                 return;
                             }
 
@@ -287,7 +287,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
 
             // Touch bar integration
             if (hasTouchBar) {
-                for (const event of [ "bold", "italic", "underline", "paragraph", "heading" ]) {
+                for (const event of ["bold", "italic", "underline", "paragraph", "heading"]) {
                     editor.commands.get(event)?.on("change", () => this.triggerCommand("refreshTouchBar"));
                 }
             }
@@ -373,10 +373,33 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
             });
         }
     }
+    // old version
+    // insertDateTimeToTextCommand() {
+    //     const date = new Date();
+    //     const dateString = utils.formatDateTime(date);
 
-    insertDateTimeToTextCommand() {
+    //     this.addTextToEditor(dateString);
+    // }
+
+    // new version
+    async insertDateTimeToTextCommand() { 
         const date = new Date();
-        const dateString = utils.formatDateTime(date);
+        let userPreferredFormat = "";
+
+        try {
+
+            await options.initializedPromise;
+
+            const customFormatFromSettings = options.get("customDateTimeFormatString");
+
+            if (typeof customFormatFromSettings === 'string') { 
+                userPreferredFormat = customFormatFromSettings;
+            }
+        } catch (e: any) {
+            console.error("TriliumNext: Error during options initialization or getting custom date/time format. Using default.", e);
+        }
+
+        const dateString = utils.formatDateTime(date, userPreferredFormat);
 
         this.addTextToEditor(dateString);
     }
diff --git a/apps/client/src/widgets/type_widgets/options/text_notes/date_time_format.ts b/apps/client/src/widgets/type_widgets/options/text_notes/date_time_format.ts
new file mode 100644
index 000000000..5a16b3d2c
--- /dev/null
+++ b/apps/client/src/widgets/type_widgets/options/text_notes/date_time_format.ts
@@ -0,0 +1,80 @@
+import OptionsWidget from "../options_widget.js"; // Path might need adjustment
+import { t } from "../../../../services/i18n.js"; // For internationalization, if you want to use it
+import type { OptionMap } from "@triliumnext/commons"; // For typing the options object
+
+// Using t() for translatable strings is good practice if the project uses it.
+// If not, you can use plain strings.
+const TPL = /*html*/`
+<div class="options-section">
+    <h4>${t("options.customDateTimeFormatTitle", "Custom Date/Time Format (Alt+T)")}</h4>
+
+    <p>
+        ${t("options.customDateTimeFormatDesc1", "Define a custom format for the date and time inserted using the Alt+T shortcut.")}
+        ${t("options.customDateTimeFormatDesc2", "Uses <a href=\"https://day.js.org/docs/en/display/format\" target=\"_blank\" rel=\"noopener noreferrer\">Day.js format tokens</a>. Refer to the Day.js documentation for valid tokens.")}
+    </p>
+    <p>
+        <strong>${t("options.customDateTimeFormatImportant", "Important:")}</strong>
+        ${t("options.customDateTimeFormatDesc3", "If you provide a format string that Day.js does not recognize (e.g., mostly plain text without valid Day.js tokens), 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;">
+            ${t("options.customDateTimeFormatLabel", "Format String:")}
+        </label>
+        <input type="text" id="customDateTimeFormatInput" class="form-control custom-datetime-format-input" 
+               placeholder="${t("options.customDateTimeFormatPlaceholder", "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>${t("options.customDateTimeFormatExamplesLabel", "Examples of valid Day.js formats:")}</em>
+        <code>YYYY-MM-DD HH:mm</code> (${t("options.customDateTimeFormatExampleDefault", "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 {
+    // Declare class properties with types if needed (jQuery objects are often typed as JQuery<HTMLElement>)
+    private $formatInput!: JQuery<HTMLInputElement>; // The "!" is a non-null assertion operator
+
+    doRender() {
+        this.$widget = $(TPL); // $ is jQuery, ensure it's available (likely is if OptionsWidget uses it)
+        this.$formatInput = this.$widget.find(
+            "input.custom-datetime-format-input"
+        ) as JQuery<HTMLInputElement>; // Type assertion for jQuery result
+
+        this.$formatInput.on("input", () => {
+            const formatString = this.$formatInput.val() as string; // Get value, assert as string
+            this.updateOption("customDateTimeFormatString", formatString);
+        });
+
+        return this.$widget;
+    }
+
+    async optionsLoaded(options: OptionMap) { // Use the imported OptionMap type
+        const currentFormat = options.customDateTimeFormatString || "";
+
+        if (this.$formatInput) {
+            this.$formatInput.val(currentFormat);
+        } else {
+            // Fallback logic as before, ensure $widget is available if $formatInput isn't yet
+            console.warn(
+                "TriliumNext DateTimeFormatOptions: $formatInput not initialized when optionsLoaded was called. Attempting to find again."
+            );
+            const inputField = this.$widget?.find( // Optional chaining for $widget
+                "input.custom-datetime-format-input"
+            ) as JQuery<HTMLInputElement> | undefined; // Result could be undefined
+
+            if (inputField?.length) { // Optional chaining and check length
+                this.$formatInput = inputField;
+                this.$formatInput.val(currentFormat);
+            } else {
+                console.error(
+                    "TriliumNext DateTimeFormatOptions: Could not find format input field in optionsLoaded."
+                );
+            }
+        }
+    }
+}
diff --git a/apps/server/src/routes/api/options.ts b/apps/server/src/routes/api/options.ts
index 4b7ce655d..cd34c1693 100644
--- a/apps/server/src/routes/api/options.ts
+++ b/apps/server/src/routes/api/options.ts
@@ -84,6 +84,7 @@ const ALLOWED_OPTIONS = new Set<OptionNames>([
     "redirectBareDomain",
     "showLoginInShareTheme",
     "splitEditorOrientation",
+    "customDateTimeFormatString",
 
     // AI/LLM integration options
     "aiEnabled",
diff --git a/packages/commons/src/lib/options_interface.ts b/packages/commons/src/lib/options_interface.ts
index 19125d125..d898ddad2 100644
--- a/packages/commons/src/lib/options_interface.ts
+++ b/packages/commons/src/lib/options_interface.ts
@@ -47,6 +47,7 @@ export interface OptionDefinitions extends KeyboardShortcutsOptions<KeyboardActi
     passwordDerivedKeySalt: string;
     encryptedDataKey: string;
     hoistedNoteId: string;
+    customDateTimeFormatString: string;
 
     // Multi-Factor Authentication
     mfaEnabled: boolean;