Is 2028 a Leap Year?

2028 is a leap year

The rule has three clauses, and only the third catches anyone out. A year is a leap year if it divides by 4; except that a century year is not, unless it also divides by 400. 2028 divides by 4, so it has a 29 February and 366 days.

2000 was a leap year and 1900 was not, for exactly this reason — the pair of them is the cleanest demonstration of the rule, and the source of a well-known class of software bug. The next leap year after 2028 is 2032, and the previous one was 2024. Because 2028 has a leap day, a date after 29 February moves forward two weekdays into 2029 rather than one.

The rule has three clauses because the tropical year is about 365.2422 days long, not 365.25. Adding a day every four years overshoots by roughly eleven minutes a year, which is three days every four centuries — so the Gregorian reform dropped three leap days per 400 years by skipping the century years that do not divide by 400. That is the whole of it, and 2028 is in the set that keeps its extra day.

What it means in practice: someone born on 29 February 2028 has a calendar birthday only every four years, and most institutions treat 28 February or 1 March as the anniversary in between. That clamping rule is the same one the date calculator applies to every month end, and it is written out on the methodology page.

2028 at a glance

Every convention used above — whether the start date counts, how month ends are clamped, which holidays close an office — is written out on the methodology page, including the ISO 8601 week rule and the leap-year rule in full.