Yay, working on a Sunday

So, I have a deadline Tommorrow AM, which means that i'm in the office today working on stuff to make sure I get it finished. The deliverable doesnt seem to be a Really Big Deal, but it involves using and adding onto a bunch of other peoples spreadsheets. As a new and unknown entity, I'm assuming that people will look at this and use it as a basis for a first impression.  In order to meet (exceed?) expectations I need to rock the analysis, which in turn means that I must first figure out What Did They Do, and Why they did it that way? Then, I have to add onto their work. Not so tough, but the 'spinning up' of figuring out the whats and why's from pages of numbers takes a bit of time.