I am creating my WordPress theme... This way I can get the month when the post was published as a string:
<?php the_time('j'); ?>
Now I need only the first 3 characters of this string.
For example: JANUARY should be JAN, APRIL should be APR...
"M - Textual three letters Jan - Dec"
https://codex.wordpress.org/Formatting_Date_and_Time
In that case:
<?php the_time('M'); ?>
Will be ok.