WordPress at a glance
function is not described

get_post_datetime() WP 5.3.0

Retrieve post published or modified time as a DateTimeImmutable object instance.

The object will be set to the timezone from WordPress settings.

For legacy reasons, this function allows to choose to instantiate from local or UTC time in database. Normally this should make no difference to the result. However, the values might get out of sync in database, typically because of timezone setting changes. The parameter ensures the ability to reproduce backwards compatible behaviors in such cases.

No Hooks.

Return

DateTimeImmutable/false. Time object on success, false on failure.

Usage

get_post_datetime( $post, $field, $source );
$post(int/WP_Post)
WP_Post object or ID.
Default: global $post object
$field(string)
Published or modified time to use from database. Accepts 'date' or 'modified'.
Default: 'date'
$source(string)
Local or UTC time to use from database. Accepts 'local' or 'gmt'.
Default: 'local'

Changelog

Since 5.3.0 Introduced.

Code of get_post_datetime() WP 5.5.1

<?php
function get_post_datetime( $post = null, $field = 'date', $source = 'local' ) {
	$post = get_post( $post );

	if ( ! $post ) {
		return false;
	}

	$wp_timezone = wp_timezone();

	if ( 'gmt' === $source ) {
		$time     = ( 'modified' === $field ) ? $post->post_modified_gmt : $post->post_date_gmt;
		$timezone = new DateTimeZone( 'UTC' );
	} else {
		$time     = ( 'modified' === $field ) ? $post->post_modified : $post->post_date;
		$timezone = $wp_timezone;
	}

	if ( empty( $time ) || '0000-00-00 00:00:00' === $time ) {
		return false;
	}

	$datetime = date_create_immutable_from_format( 'Y-m-d H:i:s', $time, $timezone );

	if ( false === $datetime ) {
		return false;
	}

	return $datetime->setTimezone( $wp_timezone );
}