diff --git a/l10n/en-US/viewer.ftl b/l10n/en-US/viewer.ftl
index 9dcde08c59974a..67b6682cc04274 100644
--- a/l10n/en-US/viewer.ftl
+++ b/l10n/en-US/viewer.ftl
@@ -283,9 +283,8 @@ pdfjs-rendering-error = An error occurred while rendering the page.
 ## Annotations
 
 # Variables:
-#   $date (Date) - the modification date of the annotation
-#   $time (Time) - the modification time of the annotation
-pdfjs-annotation-date-string = { $date }, { $time }
+#   $dateObj (Date) - the modification date and time of the annotation
+pdfjs-annotation-date-string1 = { DATETIME($dateObj, dateStyle: "short") }, { DATETIME($dateObj, timeStyle: "medium") }
 
 # .alt: This is used as a tooltip.
 # Variables:
diff --git a/l10n/sv-SE/viewer.ftl b/l10n/sv-SE/viewer.ftl
index 51ee046b6a209f..30fa7f7e9ba3a4 100644
--- a/l10n/sv-SE/viewer.ftl
+++ b/l10n/sv-SE/viewer.ftl
@@ -264,9 +264,9 @@ pdfjs-rendering-error = Ett fel uppstod vid visning av sidan.
 ## Annotations
 
 # Variables:
-#   $date (Date) - the modification date of the annotation
-#   $time (Time) - the modification time of the annotation
-pdfjs-annotation-date-string = { $date } { $time }
+#   $dateObj (Date) - the modification date and time of the annotation
+pdfjs-annotation-date-string1 = { DATETIME($dateObj, dateStyle: "short") }, { DATETIME($dateObj, timeStyle: "medium") }
+
 # .alt: This is used as a tooltip.
 # Variables:
 #   $type (String) - an annotation type from a list defined in the PDF spec
diff --git a/src/display/annotation_layer.js b/src/display/annotation_layer.js
index dff737b6ca6d72..201e65332ba77b 100644
--- a/src/display/annotation_layer.js
+++ b/src/display/annotation_layer.js
@@ -2242,13 +2242,12 @@ class PopupElement {
       modificationDate.classList.add("popupDate");
       modificationDate.setAttribute(
         "data-l10n-id",
-        "pdfjs-annotation-date-string"
+        "pdfjs-annotation-date-string1"
       );
       modificationDate.setAttribute(
         "data-l10n-args",
         JSON.stringify({
-          date: this.#dateObj.toLocaleDateString(),
-          time: this.#dateObj.toLocaleTimeString(),
+          dateObj: this.#dateObj.valueOf(),
         })
       );
       header.append(modificationDate);