This is a script I threw together a while ago that tries to calculate the "real" date for Presidents' Day with some sort of circular average thing instead of naively averaging all their birthdays. For extra fun, I also had it weight each president's contribution via total days in office, net favorability rating, or a combination of both.
Sample output, as of 2018-02-19:
To get this result, append 45,Donald Trump,1946-06-14,"396",-14 to the CSV.
Weighted (Days): 2000-02-28
Weighted (Favorability): 2000-02-23
Weighted (both): 2000-02-26
Unweighted: 1999-12-05
Sample output, excluding Donald Trump (am too lazy to make the script auto calculate days in office and all):
Weighted (Days): 2000-02-25
Weighted (Favorability): 2000-02-26
Weighted (both): 2000-02-26
Unweighted: 1999-12-07