Drupal 7.31, String Overrides 7.x-1.8

We work for a higher education institute where all publications, even websites, are to adhere to APA style. The problem is that PHP date format only supports am/pm and AM/PM but not the APA style a.m./p.m. We have tried numerous methods of replacing the "am" with "a.m." unsuccessfully, and the String Overrides module is our last resort at this time.

We are using !ampm-abbreviation am|pm|AM|PM to !ampm-abbreviation a.m.|p.m.|A.M.|P.M. and so far it seems to be working with Nodes and Views Pages; however, it is not changing the am/pm in View Blocks inserted into a Panel page. Is there a way to get overrides to work on Blocks, especially View Blocks?