diff --git a/plinth/modules/backups/views.py b/plinth/modules/backups/views.py
index a05c73ac6..a7d1424dd 100644
--- a/plinth/modules/backups/views.py
+++ b/plinth/modules/backups/views.py
@@ -130,8 +130,11 @@ class CreateArchiveView(SuccessMessageMixin, FormView):
         if repository.flags.get('mountable'):
             repository.mount()
 
-        name = form.cleaned_data['name'] or datetime.now().strftime(
-            '%Y-%m-%d:%H:%M')
+        name = form.cleaned_data['name']
+        if not name:
+            name = datetime.now().astimezone().replace(
+                microsecond=0).isoformat()
+
         selected_apps = form.cleaned_data['selected_apps']
         repository.create_archive(name, selected_apps)
         return super().form_valid(form)