@nthompson406 - you are mixing up two separate rules.
1) you are eligible for a tax exemption on the capital gain if you lived in the home at least 2 of the last 5 years. In your case, you would be eligible for a pro-ration of that exemption, assuming you sell the home before the two years has gone by and you move to a different city due to a required job change. The capital gain is the selling price less the purchase price less the selling costs less any improvements made after you purchased the home. Then from the result you can reduce the gain by the prorated exemption. The clock on this rule begins when you are LIVING (i.e. sleeping) in this home)
2) there is short term capital gain if you owned the home for less than 1 year or a long term capital gain if you owned the home for more than a year. I'll ask others to weigh in on when the clock starts
@Carl
