Here is a function that returns the day of the week for what ever date you send to it.
// returns the day of the week, date$ is YYYY-MM-DD format
function DayOfWeek(date$)
Seconds=GetUnixFromDate(Val(Left(date$,4)),Val(Mid(date$,6,2)),Val(Right(date$,2)),0,0,0)
Day = mod(Seconds/86400,7)
select Day
case 0
Day$ = "Thursday"
endcase
case 1
Day$ = "Friday"
endcase
case 2
Day$ = "Saturday"
endcase
case 3
Day$ = "Sunday"
endcase
case 4
Day$ = "Monday"
endcase
case 5
Day$ = "Tuesday"
endcase
case 6
Day$ = "Wednesday"
endcase
endselect
endfunction Day$
What would be REALLY cool is a plugin that does formatting for time, date, currency, all the usual stuff that can be formatted.