How to format the date in post admin??

How did you add the custom column? Is there a call to the date() function in the code for that? If not, what code causes the date to display?

this is the code i have in my functions file

// Register the column
function revised_column_register( $columns ) {
    $columns['revised'] = 'Revised';
    return $columns;
}

add_filter( 'manage_edit-post_columns', 'revised_column_register' );

// Display the column content
function revised_column_display( $column_name, $id ) {
    if ('revised' == $column_name)
        echo get_post_field('post_modified', $id);
}
add_action( 'manage_posts_custom_column', 'revised_column_display', 10, 2 );

// Register the column as sortable
function revised_column_register_sortable( $columns ) {
	$columns['revised'] = 'modified';

	return $columns;
}
add_filter( 'manage_edit-post_sortable_columns', 'revised_column_register_sortable' );

function revised_column_orderby( $vars ) {
	if ( isset( $vars['orderby'] ) && 'revised' == $vars['orderby'] ) {
		$vars = array_merge( $vars, array(
			'orderby' => 'revised'
		) );
	}

	return $vars;
}
add_filter( 'request', 'revised_column_orderby' );

I got it from an article i found here

Custom Sortable columns

I can’t seem to see where the code is that controls the date format though. Thanks for taking the time to reply, much appreciated.

I think you need to change this:

echo get_post_field('post_modified', $id);

to this:

echo date('n/j/Y',strtotime(get_post_field('post_modified', $id)));

You did not specify the format you wanted, so I set it to ‘n/j/Y’ to print the date like ‘3/6/2010’. Change that as desired. The link below has a table of the format codes:

https://php.net/manual/en/function.date.php

Thanks vtxyzzy, worked perfectly!!!

All the best!