Is 2000 a leap year?

Yes, the year 2000 is indeed a leap year. A leap year is a year that contains an extra day, February 29th, which is added to the calendar to synchronize it with the Earth's orbit around the Sun. To determine if a year is a leap year, we follow a set of rules:

• Divisibility by 4 Rule: If a year is evenly divisible by 4, it has the potential to be a leap year. In the case of 2000, it passes this rule since 2000 ÷ 4 = 500 with no remainder.
• Divisibility by 100 Rule: However, a further condition applies. If a year is divisible by 100 but not divisible by 400, then it's not a leap year. This rule accounts for a more accurate synchronization with the solar year. In the case of 2000, it satisfies this rule as well since 2000 ÷ 100 = 20 with no remainder, but it also passes the next rule.
• Divisibility by 400 Rule: If a year is divisible by 400, it's considered a leap year, regardless of the divisibility by 100 rule. This rule is the reason why 2000 is a leap year. Since 2000 ÷ 400 = 5 with no remainder, it's a leap year.

The decision to make 2000 a leap year is significant because it was a "century year." Century years are usually not leap years according to the second rule, but the third rule (divisibility by 400) overrides this in exceptional cases. This was done to bring the calendar year length even closer to the solar year length.

In practical terms, adding an extra day to February in a leap year (as done in 2000) helps to maintain the accuracy of our calendars by accounting for the fraction of a day that is not accounted for in the 365-day calendar year.

In summary, 2000 is a leap year due to its divisibility by 400, even though it's a century year. This adjustment ensures that our calendars remain aligned with the Earth's orbit, making our timekeeping accurate and reliable.