HP 3000 Manuals

HP ALLBASE/4GL Developer Reference Manual Vol. 2

Using Dates 

HP ALLBASE/4GL stores and uses dates internally in the form YY/MM/DD,
where YY is the year, MM is the month, and DD is the day.  If you need to
use a literal to express a date in a logic command, you must express the
date in the format YY/MM/DD.

MPE/iX 5.0 Documentation