I do need to make a billing in Mid-June for the 1H-Year for the customers. The period to calculate is from the opening or 01.01. of the relationsship to the End of June (30.06.). This has to be done every year, so I cannot use 30.06.2002 to calculate the DatDiff. But if I use only 30.06., the system reports an error. I actually use
If([J]=[Jr] and [Mt] between 1 and 6;DatDiff("t";[Opening];"30.06.##");"180")
Any idea how to solve the problem?