Here we check the valid strings for the argument of the Date:: class constructor to create Date object under JavaScript, ie,

<script type="text/javascript">
var objDate;
objDate = new Date("Dec 21, 2024 15:57:21 GMT+0100");
<script>

We are trying to get the PHP date format string to format date time to form the pipeline PHP DateTime() => js Date() => document.write() to output on screen. Here is the summary of cases we tested for you:

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
0	Dec 21, 2024 15:57:21 GMT+0100	+	+	+	+	+	+
1	Dec 21 2024 15:57:21 GMT+0100	+	+	+	+	+	+
2	Dec 21, 2024 15:57:21 GMT+1	+	+	+	+	+	+
3	2024-12-21 15:57:21 GMT+0100	-	+	-	-	+	+
4	2024-12-21 15:57:21 GMT+01:00	-	+	-	-	+	+
5	2024-12-21 15:57:21 GMT+100	-	+	-	-	+	+
6	21 Dec 2024 15:57:21+01:00	-	+	-	-	-	-
7	Dec 21 2024 15:57:21 GMT+1:00	-	+	+	-	+	+
8	Dec 21, 2024 15:57:21 GMT+01:00	-	+	+	-	+	+
9	2024-12-21 15:57:21 GMT+1	-	+	-	-	+	+
10	2024-12-21 15:57:21	-	+	-	-	+	+
11	2024-12-21T15:57:21+01:00	+	+	+	+	+	-
12	2024-12-21 15:57:21+01:00	-	+	-	-	-	-
13	12-21-2024 15:57:21 GMT+0100	+	+	-	-	-	+
14	12/21, 2024 15:57:21 GMT+0100	+	+	+	-	+	+
15	21-Dec-2024 15:57:21 GMT+0100	-	+	-	+	-	+

Tab. I: + Valid Date Time String for Javascript::Date() class, - Invalid.

JavaScript is very English speaking. In effect, among the 3 first universal formats, the English month abbreviation is used. As it can be observed that no pure numerical date string is found like "2024-12-21 15:57:21" to fit JavaScript syntax in all browsers. Please check this with your preferred browser.

Detail of JavaScript Tests

Below, the bold date time outputs at the right hand side of => are the JavaScript Date Class results.

0. Good Format "mmm dd, yyyy hh:mm:ss GMT+0200"

For example, Dec 21, 2024 15:57:21 GMT+0100 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
0	Dec 21, 2024 15:57:21 GMT+0100	+	+	+	+	+	+

This format is valid for all browsers in our hands, including Internet Explorer, Google Chrome, Firefox, Safari, Opera, Mobile Safari. On PHP, you get this DateTime format of the current time by

<?php
$objDateTime = new DateTime();
$strDateTime = $objDateTime->format("M d, Y H:i:s \G\M\TO");
?>

One observes that this is the Standard English Date Time expression.

1. Another Good Format "mmm dd yyyy hh:mm:ss GMT+0200"

For example, Dec 21 2024 15:57:21 GMT+0100 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
1	Dec 21 2024 15:57:21 GMT+0100	+	+	+	+	+	+

This format is also valid for all browsers in our hands, including IE, Google Chrome, Firefox, Safari, Opera, Safari Mobile. On PHP, you get this DateTime format of the current time by

<?php
$objDateTime = new DateTime();
$strDateTime = $objDateTime->format("M d Y H:i:s \G\M\TO");
?>

One notes that this is another English Date Time expression with timezone.

2. Good Format "mmm dd, yyyy hh:mm:ss GMT+2"

For example, Dec 21, 2024 15:57:21 GMT+1 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
2	Dec 21, 2024 15:57:21 GMT+1	+	+	+	+	+	+

As shown, you can shorten the timezone notification.

Bad Formats

All following date time strings are good for some browsers, but unfortunately bad for others.

3. Format "yyyy-mm-dd hh:mm:ss GMT+0200"

For example, 2024-12-21 15:57:21 GMT+0100 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
3	2024-12-21 15:57:21 GMT+0100	-	+	-	-	+	+

4. Format "yyyy-mm-dd hh:mm:ss GMT+02:00"

For example, 2024-12-21 15:57:21 GMT+01:00 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
4	2024-12-21 15:57:21 GMT+01:00	-	+	-	-	+	+

4. Format "yyyy-mm-dd hh:mm:ss GMT+0200"

For example, 2024-12-21 15:57:21 GMT+01:00 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
5	2024-12-21 15:57:21 GMT+100	-	+	-	-	+	+

6. Format "dd mmm yyyy hh:mm:ss+02:00"

For example, 21 Dec 2024 15:57:21+01:00 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
6	21 Dec 2024 15:57:21+01:00	-	+	-	-	-	-

7. Format "mmm dd yyyy hh:mm:ss GMT+02:00"

For example, Dec 21 2024 15:57:21 GMT+1:00 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
7	Dec 21 2024 15:57:21 GMT+1:00	-	+	+	-	+	+

8. Format "mmm dd, yyyy hh:mm:ss GMT+02:00"

For example, Dec 21, 2024 15:57:21 GMT+01:00 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
8	Dec 21, 2024 15:57:21 GMT+01:00	-	+	+	-	+	+

9. Format "yyyy-mmm-dd hh:mm:ss GMT+2"

For example, 2024-12-21 15:57:21 GMT+1 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
9	2024-12-21 15:57:21 GMT+1	-	+	-	-	+	+

10. Format "yyyy-mmm-dd hh:mm:ss"

For example, 2024-12-21 15:57:21 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
10	2024-12-21 15:57:21	-	+	-	-	+	+

11. Format "yyyy-mmm-ddThh:mm:ss+02:00"

For example, 2024-12-21T15:57:21+01:00 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
11	2024-12-21T15:57:21+01:00	+	+	+	+	+	-

You get this format by PHP5 DateTime=>format('c'). It's regrettable that JavaScript Mobile Safari does not support this format, as this is the universal date time string, used by SQL server, MySQL Server, ...

12. Format "yyyy-mmm-dd hh:mm:ss GMT+02:00"

For example, 2024-12-21 15:57:21+01:00 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
12	2024-12-21 15:57:21+01:00	-	+	-	-	-	-

13. Format "mm-dd-yyyy hh:mm:ss GMT+0200"

For example, 12-21-2024 15:57:21 GMT+0100 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
13	12-21-2024 15:57:21 GMT+0100	+	+	-	-	-	+

14. Format "mm/dd, yyyy hh:mm:ss GMT+0200"

For example, 12/21, 2024 15:57:21 GMT+0100 =>

#	js new Date() Feed	IE	Chrome	Firefox	Safari	Opera	Mobile
14	12/21, 2024 15:57:21 GMT+0100	+	+	+	-	+	+

JavaScript new Date() running results at one single glance under Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)

Below, we summarize the date time feed checked above in a single table under your current browser.

#	PHP DateTime->format	js new Date() Feed
0	M d, Y H:i:s \G\M\TO	Dec 21, 2024 15:57:21 GMT+0100
1	M d Y H:i:s \G\M\TO	Dec 21 2024 15:57:21 GMT+0100
2		Dec 21, 2024 15:57:21 GMT+1
3	Y-m-d H:i:s \G\M\TO	2024-12-21 15:57:21 GMT+0100
4	Y-m-d H:i:s \G\M\TP	2024-12-21 15:57:21 GMT+01:00
5		2024-12-21 15:57:21 GMT+100
6	d M Y H:i:s \G\M\TP	21 Dec 2024 15:57:21+01:00
7		Dec 21 2024 15:57:21 GMT+1:00
8	M d Y H:i:s \G\M\TP	Dec 21, 2024 15:57:21 GMT+01:00
9		2024-12-21 15:57:21 GMT+1
10	Y-m-d H:i:s	2024-12-21 15:57:21
11	c	2024-12-21T15:57:21+01:00
12	Y-m-d H:i:sP	2024-12-21 15:57:21+01:00
13	m-d-Y H:i:s\G\M\TO	12-21-2024 15:57:21 GMT+0100
14	m/d, Y H:i:s\G\M\TO	12/21, 2024 15:57:21 GMT+0100
15	d-M-Y H:i:s \G\M\TO	21-Dec-2024 15:57:21 GMT+0100

Tab II: Real-Time JavaScript Date() Results with different Date time feed. See php.net: date — Format a local time/date.

Here the column "PHP DateTime->format" gives the format string to be used to obtain the "js new Date() Feed" column for JavaScript Date Constructor. The last column "js new Date() outputs" is JavaScript running results given by new Date(Date-Time String):

<script type="text/javascript">
document.write(new Date("Dec 21, 2024 15:57:21 GMT+0100"));
</script>

Test Valid Date String for JavaScript