So let's say that Google decided to repeat the event every 365 days, using the analog of a perfect 7-day week as you did above. That means that every 4 years, G

So let's say that Google decided to repeat the event every 365 days, using the analog of a perfect 7-day week as you did above. That means that every 4 years, Google's "birthday" is going to fall one day further behind your friend's actual birthday, which is clearly incorrect. I think the correct answer, as was stated above, is to simply ask someone whether they want this to repeat annually on Feb. 28 excepting leap years OR if they can accept the 4-year cycle.