diff --git a/modules/timestamp/tests/test_format_date.c b/modules/timestamp/tests/test_format_date.c
index 0effb9bd23d..17617f836f7 100644
--- a/modules/timestamp/tests/test_format_date.c
+++ b/modules/timestamp/tests/test_format_date.c
@@ -81,6 +81,11 @@ Test(format_date, test_format_date_with_timestamp_argument_formats_it_using_strf
   assert_template_format("$(format-date %Y-%m-%dT%H:%M:%S 1667500613)", "2022-11-03T19:36:53");
 }
 
+Test(format_date, test_format_date_with_timestamp_argument_using_fractions_and_timezone_works)
+{
+  assert_template_format("$(format-date %Y-%m-%dT%H:%M:%S 1667500613.613+05:00)", "2022-11-03T23:36:53");
+}
+
 Test(format_date, test_format_date_with_time_zone_option_overrrides_timezone)
 {
   assert_template_format("$(format-date --time-zone PST8PDT %Y-%m-%dT%H:%M:%S 1667500613)", "2022-11-03T11:36:53");
diff --git a/modules/timestamp/tf-format-date.c b/modules/timestamp/tf-format-date.c
index a67f4a18068..37b6c1958df 100644
--- a/modules/timestamp/tf-format-date.c
+++ b/modules/timestamp/tf-format-date.c
@@ -117,11 +117,12 @@ tf_format_date_call(LogTemplateFunction *self, gpointer s, const LogTemplateInvo
   if (state->super.argc != 0)
     {
       const gchar *ts = args->argv[0]->str;
-      if (!type_cast_to_datetime_msec(ts, &msec, NULL))
-        msec = 0;
-      ut.ut_sec = msec / 1000;
-      ut.ut_usec = (msec % 1000) * 1000;
-      ut.ut_gmtoff = -1;
+      if (!type_cast_to_datetime_unixtime(ts, &ut, NULL))
+        {
+          ut.ut_sec = 0;
+          ut.ut_usec = 0;
+          ut.ut_gmtoff = -1;
+        }
     }
   else
     {