Home/ Questions/Q 6119229
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-23T15:31:42+00:00

I am trying to calculate daysbetween difference between two dates in the grid. This

  • 0

I am trying to calculate daysbetween difference between two dates in the grid.
This kind’a works but produces at first strange result:
This is Oncalculate fields event of the TEMP table:

TEMP.FieldByName('DAYS').asstring := IntToStr(Daysbetween(TEMP.FieldByName('BIV_OD').AsDateTime,TEMP.FieldByName('BIV_DO').AsDateTime));

BIV_OD and BIV_DO are date fields (ie. like … Date_From – Date-to)
When I select the first date in the grid (BIV_OD) ,my DAYS field at first show 40731 (??)
Then when i input the second date everything works ok.
Why is that ?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    That’s what you asked for…

    Delphi stores dates as the number of days since 31/12/1899 so when you write the first date you are doing 40731(The number of days since 31/12/1899) – 0 since you haven’t yet entered a second date.

    The solution would be not to calculate the field unless both dates are filled in.

    if (Temp.FieldByName('BIV_OD').AsDateTime > 0) and (TEMP.FieldByName('BIV_DO').AsDateTime > 0) then
    TEMP.FieldByName('DAYS').AsString:= IntToStr(Daysbetween(TEMP.FieldByName('BIV_OD').AsDateTime,TEMP.FieldByName('BIV_DO').AsDateTime))
else
    TEMP.FieldByName('DAYS').AsString:= ''; //don't display anything.

    Although I’d set the grid column to have a data type of integer.

    if (Temp.FieldByName('BIV_OD').AsDateTime > 0) and (TEMP.FieldByName('BIV_DO').AsDateTime > 0) then
    TEMP.FieldByName('DAYS').AsInteger:= Daysbetween(TEMP.FieldByName('BIV_OD').AsDateTime,TEMP.FieldByName('BIV_DO').AsDateTime)
else
    TEMP.FieldByName('DAYS').Value := Null; //don't display anything.
    • 0