You are welcome.

If you use something like this make sure there are no gaps in the data.

There has to be an entry for every hour of the day otherwise you will get wrong results.

We have used this technique several times and it works well.

( although I have not used it to hour granularity, which is of no importance )

In the largest "time-cost" tables we have like 3mil rows and it works like a charm.

The logic to do calculations without these supporting tables would be horrenduos,

and the processing time terrible.

/rockmoose