Quick answer
Days until Leap Day = the date of the next Leap Day minus your start date. Counting from 10 March 2024 the next one is Tuesday 29 February 2028, which is 1451 days away.
Pick a start date (it defaults to today). The calculator returns the days, the weeks and days, and the weekday of the date.
Related tools: Days Until Labor Day: Days until US Labor Day (first Monday of September). Days Until Father's Day: Days until US Father's Day (third Sunday of June). Days Until Mother's Day: Days until US Mother's Day (second Sunday of May).
How to use the Days Until Leap Day
- Optionally, pick counting from.
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Counting from (optional) | A calendar date. Leave blank to use today's date | — |
Formula and method
Formula
days = next occurrence of 29 February (next leap year) − start date
Exact integer day arithmetic in UTC.
Finds the next occurrence of 29 February (next leap year) on or after the start date using its calendar rule. Dates follow the proleptic Gregorian calendar.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Counting from = 2024-03-10.
| Result | Value |
|---|---|
| Days Until Leap Day | 1451 days |
| Date | 2028-02-29 |
| Weekday | Tuesday |
| Weeks and days | 207 weeks, 2 days |
Example 2
Inputs: Counting from = 2024-02-01.
| Result | Value |
|---|---|
| Days Until Leap Day | 28 days |
| Date | 2024-02-29 |
| Weekday | Thursday |
| Weeks and days | 4 weeks, 0 days |
The first line is the headline result (days Until Leap Day). Below it the days Until Leap Day lists date, weekday and weeks and days, which describe the same case from other angles. Exact integer day arithmetic in UTC.
About Leap Day
Leap Day is 29 February, which exists only in leap years: years divisible by 4, except century years not divisible by 400. So 2100 is not a leap year, but 2000 was.
The next dates
Upcoming dates: Tuesday 29 February 2028; Sunday 29 February 2032; Friday 29 February 2036. The count is zero on the day itself, and once this year's date has passed the calculator moves on to the next one.
Days Until Leap Day from different start dates
The same calculator run from 1 January of four consecutive years.
| Counting from | Days Until Leap Day | Date | Weekday |
|---|---|---|---|
| 2026-01-01 | 789 | 2028-02-29 | Tuesday |
| 2027-01-01 | 424 | 2028-02-29 | Tuesday |
| 2028-01-01 | 59 | 2028-02-29 | Tuesday |
| 2029-01-01 | 1154 | 2032-02-29 | Sunday |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Counting from: entering "2024-02-30" shows "Counting from must be a valid date." beside that field and no result.
Choosing between the Days Until Leap Day and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Days Until Labor Day](/date-calendar/days-until-labor-day/) | Days Until Labor Day | |
| [Days Until Father's Day](/date-calendar/days-until-fathers-day/) | Days Until Father's Day | |
| [Days Until Mother's Day](/date-calendar/days-until-mothers-day/) | Days Until Mother's Day | |
| [Days Until MLK Day](/date-calendar/days-until-mlk-day/) | Days Until MLK Day | |
| [Days Until Inauguration Day](/date-calendar/days-until-inauguration-day/) | Days Until Inauguration Day |
Background: date rules
Holiday dates are defined in three ways: a fixed day of the month, a weekday position such as the fourth Thursday of November, or a calendar calculation such as the date of Easter. Counts are in whole calendar days from the start date, and the date is the calendar date, not adjusted for your time zone or for days a workplace observes instead.
Assumptions and limitations
- Counting on the holiday itself gives 0
- After the date has passed this year the next year's date is used
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for counting from to confirm this.
Frequently asked questions
How many days until Leap Day from today?
Enter today as the start date. From 10 March 2024 the answer is 1451 days.
What day of the week is it next year?
Upcoming weekdays: Tuesday 29 February 2028; Sunday 29 February 2032; Friday 29 February 2036.
What does the Days Until Leap Day calculate?
Days until 29 February (next leap year). It returns Days Until Leap Day, Date, Weekday and Weeks and days.
What formula does the Days Until Leap Day use?
days = next occurrence of 29 February (next leap year) − start date. Finds the next occurrence of 29 February (next leap year) on or after the start date using its calendar rule.
What is an example of a days Until Leap Day result?
With counting from 2024-03-10, the days Until Leap Day is 1451 days.
Related calculators
- Days Until Labor Day — Days until US Labor Day (first Monday of September).
- Days Until Father's Day — Days until US Father's Day (third Sunday of June).
- Days Until Mother's Day — Days until US Mother's Day (second Sunday of May).
- Days Until MLK Day — Days until US Martin Luther King Jr. Day (third Monday of January).
- Days Until Inauguration Day — Days until US Inauguration Day (20 January after a presidential election year).
- Days Until Presidents' Day — Days until US Washington's Birthday / Presidents' Day (third Monday of February).
- Days Until Memorial Day — Days until US Memorial Day (last Monday of May).
Sources
- US federal holiday rules: 5 U.S.C. § 6103
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.