If Im spending time trying to find something with negotiations which takes 2 weeks, or programming software which takes 3 months, can I do anything else during that time? So do the tests use all the hours of the day for normal activities?

Things like a Sleep Regulator darn well should and I dont know about official rulings but there is a clause about interruptions in the BBB4:

It then goes on to say this may not apply to all extended tests but for things like acquiring gear and programming software I can't imagine how it couldn't be picked back up. Don't quote me though, I'm just a player.

And I'm curious about an official answer because my character does quiiite a bit with software...

Except in the cases where you're explicitly not allowed to do other things, then yes, you can.

(For example - keeping a circulation going when refining reagents.) Of course, this is subject to GM approval. If you're trying to hack multiple programs, your lifestyle, modify a drove, a vehicle, and a firearm all at the same time, then no - that's not going to happen. If you're trying to go on a Shadowrun in the same week that you're also waiting for a negotiation to resolve, then yes, that's absolutely OK.