@Onguard2000 yes there is a definition for those words. during the year at what location did you spend the most nights. so, if you own two homes at the same time, it is possible that one year home A is your primary/main/principal residence and next year the other because of the nights used each year as your residence. so say A is your residence in calendar year1 for 190 days (making it your principal/primary/main home in year 1) B for the remainder. for the next 2 years you occupy B 300 days for each of those years and A for the remainder making B your primary, etc residence for those 2 years
in year 4 you occupy A for 300 nights and in year 5 you occupy A for 240 nights making it your primary, etc residence for those 2 years.
you have now occupied A for 730 nights in the 5 year period when it was your principal residence so you qualify for the home sale exclusion on A. This despite the fact that B was your principal residence for 600 nights during the 5 years and in fact occupied for 965 nights in the 5 year period. the days A was used as a residence in years 2 and 3 don't count because it was not your principal residence during those years. the days B was used as a residence in years 1, 4 and 5 don't count for B because it was not your principal residence during those years.
