I am not certain really-it depended on the year for the woman. She was gone for 6 weeks one time and I cancelled for another month and then she was out a couple of other times that same year. she broke her arm one year and was out awhile for that. She usually took off a week or two around new years and passover. And another time she took off a month to move into a condo from her house. I don't think she had a set number.
The second one was also gone from time to time for a week or two, but no real pattern. Plus they were both semi-retired the whole time I hired them for -so the woman was only in her office 2-3 days at the beginning of the week and the second one was at her office at the end of the week. Also I cancelled for work, school or just wanting a break.