which isn't picked up the the PSU "PhotoDate" field and I can't see a script that would copy the date to any other date field

Does anyone know have any ideas on bulk/batch conversion for copying from one date field to another ?
Hert, wonder if it would be practical to create a Date-Script that would allow any chosen Date field to be copied to any other date fields ?
[edit Hert; changed the title to something that better covers the topic]