I made a custom template of error 404 page. In my header.php i use the_time() function to display current date. There is some problem with 404 page because the_time() function won't work, not return any date. Why is that happen?
the_time does not display the current date, it displays the date of the current post, and 404 pages do not have a current post.
For this reason, if it ever returned a date on the 404 page then it would be a bug.
Instead you should use the PHP functions that come with PHP to display the current date and time.