Running counter using time

Hi everyone,

This is my first post and i'm looking for some advice or help. I've got a fairly standard knowledge of Excel etc and was wondering if you guys could help me out

I've got a table with two columns of information: Time (in 15min increments) and some general number figures;

I'm looking for excel to use the current time and sum the total numbers up to and including the most recent interval. E.g. at 10:30 it would add up all the figures from say 8am until 10:30?

Is this possible.

Any help would be great