When changing the event date format in the control panel, you can't use the "slash (\)" formatting that is allowed via php normally , probably because it is formatted after submission.
For instance if I wanted to use this format:
l, F jS Y \@ g:ia
The slash would be stripped and the date format would be incorrect.
However if you edit the default.php in mod_mb_events/tmpl/default.php
you can insert that manually which would result in this being displayed:
