How to change date display format on Appointments+ booking page

I searched in the forums and found this post with a neat little code snippet to add the date to my Appointments+ booking calendar

This works a charm and I think the calendar is much more user friendly this way but when I view my site on mobile it doesn't look so great. I'm wondering if it's possible to tweak the code so the date format is output differently?

Right now my calendar shows today's date as Fr 20/02/2015. Ideally I'd like it to say Fr 20 Feb, or if that's not possible then Fr 20/02 would still be a big improvement when viewing on mobile.