How to "build" a payday timestamp
I have a record consisting of two entry fields, dat.e and tim.e, and a calculation field in which I would like to "build" a timestamp so that I can do comparative calculations with other, unaltered timestamps. The built stamp, tmstmp.startin, should have the following modifications:
1) It will be shifted backwards from the dat.e entry to the first day of its pay period. (Don't know if there's a function for that, yet).
2) The time will be rounded down to the nearest quarter-hour increment of the corresponding tim.e entry, as in =Time(Hour(tim.e),Int((Minute(tim.e))/15)*15,0)
Things are muddied when I try to combine both into tmstmp.startin. Is there a way for a field to be both a Timestamp and a Calculation field? How would you approach this?