We’re using the Date module for the Zone 5 site, and we set up a custom field for events, called Start Date. We told it to display using the custom format
F jS, Y
And we were expecting October 3rd, 2008, but we got October 3, 2008 rd. Weird, right?
After much digging I found out that because S (which gives you the st, nd, rd, th bit) is not defined as a year, month, day, hour, minute, second, or timezone field, Drupal seems to think it’s a timezone field.