Hello!
I hope that someone can help me solve this tricky question:

I have an electrician counter. Every hour, every day the counter data are logged.

Year     Month     Day     Hour     Counter
2014     1     31     8 pm     6.857.660,00
2014     1     31     9 pm     6.857.820,00
2014     1     31     10 pm     6.857.970,00
2014     1     31     11 pm     6.858.110,00
2014     1     31     12 pm     6.858.270,00

By subtracting the counter data at 11 pm from the counter data at 12 pm you get the electricity produced the last hour.

I want to calculate the electricity produced every month.

I tried to use Variable in my formula to seek out the counter data at 12 pm the last day in the month, but I can´t seem to make it work.

/Anne

dateserial

the most useful CR function of them all (JMO).