Not in a leap year, such as is 2020.
When doing the lookback, you're guaranteed to cross at least 1 leap year. When looking at the "2 years" part of the 5 year look back, it can matter if it crosses a leap year.
Overall though it really doesn't matter because of the convoluted way the IRS does the math, where if it was your primary residence from the 1st to the 16th, you get to count the entire month. Sucks for February since mathimatically, the 15th day of that month is past the halfway point.
