Using Calcdate

CALCDATE should only be used with DateFormula variables. Alternatively the string should be enclosed using the <> symbols. Bad code

IF ReservEntry."Expected Receipt Date" \>
CALCDATE('-' + FORMAT("Dampener (Time)") + FirstDate)
THEN

Good code

IF ReservEntry."Expected Receipt Date" \>  
CALCDATE('<-' + FORMAT("Dampener (Time)") + FirstDate + '\>')  
THEN