O$: Date parts

[Franco Maregotto]

hi $all

I'm dealing with the Omnis function dpart(kDayofWeek,date):
it returns
Sun=1, Mon=2, .. Fri=6, Sat=0

PostGreSQL instead select DATE_PART('dow',date) returns
Sun=0, Mon=1, .. Fri=5, Sat=6

I tried to change the weekstart property in library prefs but Sunday always returns 1.
Any suggestion?

Thank you in advance
Franco