Calculate electric costs

Hi all,

I just registered here. I've got a problem, I've tried Google, but found nothing usefull.

Well here's my problem. I'm trying to calcute the electric costs with the conditions that the day price is € 0,10 per kWh (07:00-23:00) and night is €0,06 per kWh (23:00-07:00). The weekend (Friday 23:00-Mo 07:00) is also night price.

I have excel sheet with the following columns, A in format dd-mm-jj uu:mm, B MJ(Mega Joule), C kWh, D Costs/h. The data I get in column B are in hours, in MJ. So I divide that with 3,6 and I got kWh. Just for the info, we, europeans, work with comma as decimal, not with dot.

Can someone help me?

Thanks in advance