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Calculating with dates

Question asked by AlarS. on Aug 2, 2013
Latest reply on Aug 27, 2013 by philmodjunk


Calculating with dates



     Lots of googleing showed that this is very common problem but still couldn't find a solution for my problem. Basically I have a database which tracks aircraft service bulletins. I track it by flight hours and dates. With flight hours I got it working but with dates it's complicated.

     I've got these fields:

Recurrent (text) - for selecting if the bulletin is recurrent or not (Y or N)
Date (date) - date when the bulletin is applicable
PerformedC (date) - date when the bulletin was performed
IntervalY (number) - interval how often the bulletin has to be performed again (eg. 0.5 = every 6 months)
NextC (date) - calculates next date when the bulletin has to be performed

     What I need is a NextC field to calculate the next maintenance date. I tried using this calculation, but it results in jibburish:

     NextC = If ( Recurrent = "N" and PerformedC ≥ Date; "N/A"; If ( PerformedC = ""; Date + IntervalY * 365; PerformedC + IntervalY * 365))

     The next thing I need is to calculate the number of days left to the next maintenance:

     Fields are the mainly the same + LeftD. I used this calculation:

     LeftD = If ( PerformedC = "" or "N/A"; NextC - Date  ; NextC -  PerformedC )

     P.S. These calculations are correct, checked them in Excel, all it needs is to handle with dates correctly.


     If anyone could help or lead me to right direction, I couldn't be more thankful.


     Best Regards,