Remove ambiguity in the time display format in core, switches to using 24hr notation where am/pm isn't specified.

* `H:i - 09:54`
* `g:i a - 9:54 am`
* `F j, Y - January 3, 2015`

These shouldn't be used without a/A (am/AM)
* `h:i - 01:23`
* `G:i - 1:23`

Props iseulde. Fixes #31121


git-svn-id: https://develop.svn.wordpress.org/trunk@31862 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/meta-boxes.php

@@ -162,7 +162,7 @@ echo esc_html( $visibility_trans ); ?></span>
 
 <?php
 /* translators: Publish box date format, see http://php.net/date */
-$datef = __( 'M j, Y @ G:i' );
+$datef = __( 'M j, Y @ H:i' );
 if ( 0 != $post->ID ) {
 	if ( 'future' == $post->post_status ) { // scheduled for publishing at a future date
 		$stamp = __('Scheduled for: <b>%1$s</b>');
@@ -293,7 +293,7 @@ function attachment_submit_meta_box( $post ) {
 <div id="misc-publishing-actions">
 	<?php
 	/* translators: Publish box date format, see http://php.net/date */
-	$datef = __( 'M j, Y @ G:i' );
+	$datef = __( 'M j, Y @ H:i' );
 	$stamp = __('Uploaded on: <b>%1$s</b>');
 	$date = date_i18n( $datef, strtotime( $post->post_date ) );
 	?>