If I make two posts on the same day, the older post doesn’t show a date whilst the new post does. Is there any way I can make the date show up on both posts?
Try editing your theme files and changing all references for the_date() to the_time().
Likely candidates for editing include:
- index.php
- home.php
- archive.php
- category.php
- tag.php
Plus any custom page templates present in your theme.
If you use the the_date(), the full date is only shown on the newest post on a given date. Using the_time() will ensure that the date is displayed on all posts – the date irrespective of how many posts you publish in any one day.