diff --git a/apps/client/src/services/utils.ts b/apps/client/src/services/utils.ts
index ab6e45847..f5c1f465f 100644
--- a/apps/client/src/services/utils.ts
+++ b/apps/client/src/services/utils.ts
@@ -124,8 +124,23 @@ function formatDateISO(date: Date) {
     return `${date.getFullYear()}-${padNum(date.getMonth() + 1)}-${padNum(date.getDate())}`;
 }
 
-function formatDateTime(date: Date) {
-    return `${formatDate(date)} ${formatTime(date)}`;
+
+export function formatDateTime(date: Date, userSuppliedFormat?: string): string {
+    const DEFAULT_FORMAT = 'YYYY-MM-DD HH:mm';
+    const formatToUse = (typeof userSuppliedFormat === 'string' && userSuppliedFormat.trim() !== "")
+        ? userSuppliedFormat.trim()
+        : DEFAULT_FORMAT;
+
+    if (!date) {
+        date = new Date();
+    }
+
+    try {
+        return dayjs(date).format(formatToUse);
+    } catch (e: any) {
+        console.warn(`TriliumNext: Day.js encountered an error with format string "${formatToUse}". Falling back to default. Error: ${e.message}`);
+        return dayjs(date).format(DEFAULT_FORMAT);
+    }
 }
 
 function localNowDateTime() {
diff --git a/apps/client/src/translations/en/translation.json b/apps/client/src/translations/en/translation.json
index 4d39265d1..2f0c0e0a8 100644
--- a/apps/client/src/translations/en/translation.json
+++ b/apps/client/src/translations/en/translation.json
@@ -1962,5 +1962,16 @@
     "title": "Appearance",
     "word_wrapping": "Word wrapping",
     "color-scheme": "Color scheme"
+  },
+  "custom_date_time_format": {
+    "title": "Custom Date/Time Format (Alt+T)",
+    "desc1": "Define a custom format for the date and time inserted using the Alt+T shortcut.",
+    "desc2": "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.",
+    "important_label": "Important:",
+    "desc3": "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.",
+    "format_string_label": "Format String:",
+    "placeholder": "e.g., DD/MM/YYYY HH:mm:ss or dddd, MMMM D",
+    "examples_label": "Examples of valid Day.js formats:",
+    "example_default": "Default-like"
   }
 }
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 ca4ea98b2..d9c340489 100644
--- a/apps/client/src/widgets/type_widgets/editable_text.ts
+++ b/apps/client/src/widgets/type_widgets/editable_text.ts
@@ -266,7 +266,7 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
                         }
 
                         item.on("change:isOpen", () => {
-                            if (!("isOpen" in item) || !item.isOpen ) {
+                            if (!("isOpen" in item) || !item.isOpen) {
                                 return;
                             }
 
@@ -375,9 +375,24 @@ export default class EditableTextTypeWidget extends AbstractTextTypeWidget {
         }
     }
 
-    insertDateTimeToTextCommand() {
+    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..0690e77a9
--- /dev/null
+++ b/apps/client/src/widgets/type_widgets/options/text_notes/date_time_format.ts
@@ -0,0 +1,79 @@
+import OptionsWidget from "../options_widget.js"; 
+import { t } from "../../../../services/i18n.js";
+import type { OptionMap } from "@triliumnext/commons"; 
+
+
+const TPL = /*html*/`
+<div class="options-section">
+    <h4>${t("custom_date_time_format.title")}</h4>
+
+    <p>
+        ${t("custom_date_time_format.desc1")}
+        ${t("custom_date_time_format.desc2")}
+    </p>
+    <p>
+        <strong>${t("custom_date_time_format.important_label")}</strong>
+        ${t("custom_date_time_format.desc3")}
+    </p>
+
+    <div class="form-group">
+        <label for="customDateTimeFormatInput" style="margin-right: 10px;">
+            ${t("custom_date_time_format.format_string_label")}
+        </label>
+        <input type="text" id="customDateTimeFormatInput" class="form-control custom-datetime-format-input" 
+               placeholder="${t("custom_date_time_format.placeholder")}" 
+               style="width: 300px; display: inline-block;">
+    </div>
+    <p style="margin-top: 5px;">
+        <em>${t("custom_date_time_format.examples_label")}</em>
+        <code>YYYY-MM-DD HH:mm</code> (${t("custom_date_time_format.example_default")}),
+        <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 {
+    
+    private $formatInput!: JQuery<HTMLInputElement>;
+
+    doRender() {
+        this.$widget = $(TPL); 
+        this.$formatInput = this.$widget.find(
+            "input.custom-datetime-format-input"
+        ) as JQuery<HTMLInputElement>; 
+
+        this.$formatInput.on("input", () => {
+            const formatString = this.$formatInput.val() as string; 
+            this.updateOption("customDateTimeFormatString", formatString);
+        });
+
+        return this.$widget;
+    }
+
+    async optionsLoaded(options: OptionMap) {
+        const currentFormat = options.customDateTimeFormatString || "";
+
+        if (this.$formatInput) {
+            this.$formatInput.val(currentFormat);
+        } else {
+
+            console.warn(
+                "TriliumNext DateTimeFormatOptions: $formatInput not initialized when optionsLoaded was called. Attempting to find again."
+            );
+            const inputField = this.$widget?.find( 
+                "input.custom-datetime-format-input"
+            ) as JQuery<HTMLInputElement> | undefined; 
+
+            if (inputField?.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 c69f7568f..2ac1a5097 100644
--- a/apps/server/src/routes/api/options.ts
+++ b/apps/server/src/routes/api/options.ts
@@ -90,6 +90,7 @@ 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;