Date and Time Calculators

Leap Year Calculator

Check, find, or list Gregorian leap years using the century rule.

Apply the complete leap-year rule and explore nearby or ranged leap years.

Calculate with the Leap Year Calculator

Dates are validated as calendar components before calculation.

How to use the Leap Year Calculator

  1. Enter the required calendar dates, times, or rule values.
  2. Choose the counting convention or mode where offered.
  3. Select Calculate or press Enter.
  4. Review the result, basis, and limitations before using it.

Worked example

2024 and 2000 are leap years; 1900 and 2100 are common years.

Assumptions

Date-only calculations use the proleptic Gregorian calendar and ignore clock time. Elapsed-time calculations and selected-zone conversions state their time basis separately.

Limitations

  • Supported years are 1–9999.
  • Range spans are limited to 2,000 years.

Frequently asked questions

What date basis does the Leap Year Calculator use?

The result uses calendar dates unless the page explicitly describes elapsed time or a selected time zone.

Can daylight-saving time change calendar-day totals?

No. Date-only calculations use normalized UTC day numbers. Elapsed timestamp and time-zone calculations are explicitly handled separately.

Are entered dates stored?

No. Calculations run in your browser and the entered dates are not saved or sent anywhere.