Nadya,

Did you change the between() on the union too?

It also looks like this might be a "data" problem. Are you sure that all rows have a valid value in extryear?

>>between(iif(extryear<'10','20','19')+extryear+extrweek, lcBeginWeek, lcEndWeek) as currmnth,
>
> Ok, I did. The first SQL seems to work fine after this change, the second (with union) still gives me this error. In VFP6.0 or in VFP5.0 with set talk off it works without problems. I understand, that even if it's a bug, MS will not fix this version, since VFP6.0 is available, and, hopefully, VFP7.0 will be available soon. I'd rather not use VFP5.0, but I did it by my manager's request. Anyway, right now I want to stop waisting my time on this problem.
>
>Thanks for your help.