Each year has 365 days. Well, almost. Every four years (give or take), our calendars receive an additional day. So, as you're making leap day plans for this year, here's a quick primer on how it came ...

2024 is a leap year, meaning Thursday, Feb. 29 is a once-in-every-four-year event. Since leap years typically happen every four years (although there are some exceptions), our last leap days were in ...