Hello,
Thank you for contacting us and bringing your concern to our attention.
Please note that we recently changed the sitemap implementation.
The timezone will now be a constant +00:00, and the post time will be converted to match the +00:00 timezone.
If you check the posts you’ll see the Last-Modified time has been converted to the UTC timezone. This is the default behavior of the plugin and expected since a recent update.
If you still want to change the timezone then you will have to make changes directly to the plugin files. You can edit the wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/class-timezone.php
And change the UTC with your preferred timezone on line 40. Since you want UTC +05:30, the code should be like this:
$date_time = new DateTime( $datetime_string, new DateTimeZone( '+03:00' ) );
Please note that these changes will be overridden by each update and you will have to make the changes again.
Also, there is no benefit in modifying the code, as Google recommends using the UTC timezone and will be able to detect the correct last modified time. That’s why we made this change in the plugin.
Hope that helps and please don’t hesitate to let us know if you have any other questions.
