Syntax - @DOW(DateString)
Parameters - DateString Date in the format MMDDYY, with no separation.
Action - Returns the day of the week represented by the date, as a number. Monday = 1 through Sunday = 7.
Example - @DOW(012518)
Result - Returns 4, which represents Thursday, the day of the week for January 25, 2018.
See:
Filters and Formula Functions - All
Edit Variable Screen
Variables in SubTotals and Grand Totals
Filters and Formula Operators
Filters - Transaction Types