date formula

nostran
nostran Member Posts: 106
edited 2005-02-08 in NAV/Navision Classic Client
hi,

i've got a date , shipmentdate. i've got safety lead time that i get from the item card.
i need to subtract the lead time from the shipment date. the shipmentdate is a dateformula format, so is my lead time.

what i'm want to do is actually

b:= ShipmentDate - Leadtime
but i'm stuck with the syntax
i tried
DateToOrder := CALCDATE(Item."Safety Lead Time", PeriodStartDate)
but i need to subtract item."safety Lead Time" from PerodStartDate but can't figure out how :oops:
thanks

Comments

  • Wiechardt
    Wiechardt Member Posts: 25
    Nostran

    The call to calculate a new date from an existing date with a Date Formula is 100% correct. The problem here is not a syntax error, but rather a logical error.

    Think about it logically: You enter your "Safety Lead Time" on the Item Card as, for instance: 5D (5 Days).

    You then try to calculate the new date using:
    DateToOrder := CALCDATE(Item."Safety Lead Time", PeriodStartDate)

    Instead of subtracting % days from the PeriodStartDate, the system will add 5 Days.

    There are 2 solutions to this:
    1. The best solution is to construct a new "Safety Lead Time" before you calculate the date. Convert the DateFormula to Text, test for a minus sign as the first character, if no minus sign was found, add one to the beginning of the string. Convert the new text to a DateFormula using EVALUATE and then calculate the new date.
    2. Add code to the OnValidate trigger of the "Safety Lead Time" field to ensure users enter a negative date formula. (Only do this if you don't utilise any other features that uses the Safety Lead Time functionality.

    /Wiechardt
  • zarryn
    zarryn Member Posts: 29
    Or you could try...
    DateToOrder := CALCDATE('-'+Format(Item."Safety Lead Time"),PeriodStartDate);

    This should work.
    Zarryn

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