Templates

I've noticed that the date format I've set in 'Analytics, comments, typography > Date and time' is not being respected. I have it set to 'Day-Month-Year', but posts on my site are still presented with the date in 'Month Day, Year'. Can anyone give me an idea what I should be looking for in the source code that defines the date format? (I realise this will be somewhat template-dependent, and I've modified mine so much over the years that I honestly forget which it was originally forked from, Rosa maybe?)