I was looking for a way to display the exif date in the european format:
day-month-year hour:minute instead of year-day-month

Since I didn't found a setting or a solution I made a little mod in the template-function.php line 2387 and below.

Original:
`

modified:

Your code looks reasonable. Of course you need not modify the core, you can simply make your own print function under a different name by copying the code then modifying it.

There is a define for the data format set for the site: DATE_FORMAT.

Probably the cleanest solution would be to add formatting information to the $_zp_exifvars array and use that in the output function.