I’m not much of a WordPress maven, but since nobody answered your question yet I thought I’d give it a try.
I found this thread, which mentions these PHP codes.
That page lists examples like this:
The time is <?php print date("H:i") ?>.
That means it's <?php print date("i") ?>
minutes past <?php print date("H") ?> o'clock.
Which will give you an output like this:
The time is 15:26. That means it’s 26 minutes past 15 o’clock.
I tried it on my site and it worked, but it gave me output just like the example: “15 o’clock,” rather than “3 o’clock.”
The other URL mentioned in the thread says lower case “g” will give you a “12-hour format of an hour without leading zeros” and I tried this:
The time is <?php print date("g:i") ?>.
That means it's <?php print date("i") ?>
minutes past <?php print date("g") ?> o'clock.
And I got:
The time is 3:26. That means it’s 26 minutes past 3 o’clock.
I hope this helps.