sorry, I don't get it. I see you start to average the kilowatt hours for days that aren't Sunday. I don't understand the purpose of your modulus function... it looks like you're looking at the time and seeing if the formula results = the results produced by an identical formula in Col E.
You seem determined to use a array formula and that makes me wonder.. is this for school?

Hmmm. Not for school I'm an office worker. I can say I dont understand the purpose of my modulus function either, but I am using it because I couldnt figure out any other way to get the dates to read. I'd love to do away with it. Someone tossed it out as a good methodology and I took them at their word.

I am not determined to use array formulas...or any other type. It doesnt matter to me but I need it to be bomb proof!

Thanks!

Fraser