In reply to Phil VDB.

Hi,

In VA you have a magic word, it's "TreatAs". Create a calculated item.
So you want to sum some time columns? No worries, select the calculation : '+' and then go in the selection left and look after the TreatAs operation. drag it twice and add your columns you want to sum. my example is a date but it's the same : TreatAs(_Number_, 'year'n) + TreatAs(_Number_, 'year'n)
and now you need to put a TreatAs on top of whole the calculation and tell him it's a time.
job is done ;-)