To create an ISO date:
DLT-${Year}-${Month:p/2/0/r}-${Day:p/2/0/r}
on 20 June 2003 would give DLT-2003-06-20
If you set the environment variable mon to
January|February|March|April|May|...
File-${mon[${Month}]}/${Day}/${Year}
on the first of March would give File-March/1/2003