[lanna]

Unless you were born Feb 29, I guess everyone's birthday is on the same day every year. Mine, for instance, is always on Sep 11, every single year.

[ComSubVie]

You're confusing day (Monday, ...) with date (12th Dec).

[jamie_ca]

He's pointing out that those stuck on a leap day are still stuck.

If you count by day-of-year when doing the conversion, though, it's the people born new year's eve on a leap year that are impacted.