Upcoming work and short deadlines

Here is what is coming up on my plate for the next month.

There are two companies, that do something similar to timeshares, but for the rich and corporations -- only. Each has their own rules and benefit for making reservations.

My job is to merge these business rules, of making reservations, from the newly acquired company into the current application of the precedent company in which we develop for.

I have until the end of the year (80 hours) to get this done.

My experience so far has been to get up to speed and develop quickly before the deadline, because this is a last minute request.

Some examples of my recent past projects:
2 months to implement a huge list of enhancements in VB.Net 1.1,
2 months to rewrite 1,700 store procedures from dynamic to a quicker static version,
1 week to implement a parser and a new store procedure to increase input,
and now this.