iTookOff's Accounting Methods, I Need Your Help!

I've received a lot of emails lately asking about how iTookOff handles it's internal accounting. When it was originally developed, iTookOff was a much simpler app and used a (what I call) "zero-sum" style of accounting. Time would be added and deducted up front at the time of entry so that at the end of the year, you'd end up with zero. This means your time would sometimes appear as negative if you borrow against your accrual. This is obviously not always the reality and many people are confused by how it works. I'd like to remedy this to handle everyone's needs but I'd like to find out the majority of user's expectations. I need your help figuring out the best way to proceed with this. So here's where you come in. Would you prefer that future time can be added but not deducted until it actually passes? Would you prefer it to stay the same? Or would you prefer to have the option to account both ways? My immediate impression is that there will be support on either side but one side may come out on top. In either case I'd like to accommodate both types of accounting somehow. It's just a matter of which side should I center my development efforts around. Please let me know your feelings either in the comments below or by responding on the poll. If there are no votes, feelings, or comments either way, I'll just continue in the direction that I believe accommodates both sides equally. Also, if there are actual names for the types of accounting I mentioned above, or if I'm wrong about any labels I used, please feel free to correct me. Thanks everyone!