About DaysTo
DaysTo is a small collection of date calculators built around one idea: date math should be accurate, instant and completely private. Every tool runs in your browser with plain JavaScript. Nothing you enter, whether a birth date, an event date or a range, is ever sent to a server, stored or tracked.
How the calculations work
Ages and date differences
Ages and gaps between dates are measured in whole calendar days. The tools strip the time of day and count the midnights between two dates, which keeps results stable regardless of the hour and immune to daylight saving shifts. The years, months and days breakdown uses natural borrowing, counting whole years first, then whole months, then leftover days, exactly the way people state a duration out loud.
Leap years
A leap year adds February 29 to keep the calendar aligned with the solar year of roughly 365.2422 days. Years divisible by four are leap years, except century years, which must also be divisible by 400. That is why 2000 was a leap year and 1900 was not. Because every calculation counts real calendar days, leap days inside a range are always included automatically.
Week numbers
The week number tool follows ISO 8601, the international standard used by most software and businesses. Weeks start on Monday, and week 1 is the week containing the year's first Thursday, which is also the week containing January 4. Most years have 52 weeks and some have 53.
Business days
The business-day count includes Monday through Friday and skips weekends. Public holidays are left in, because holiday calendars differ by country and region, so the figure represents the working-week baseline that you can adjust for any local holidays.
Holiday countdowns
Fixed holidays such as Christmas are simple lookups. Moving holidays are resolved by rule: Thanksgiving is the fourth Thursday of November, Memorial Day is the last Monday of May, and so on. Easter and the dates tied to it use the standard Gregorian computus, the same algorithm used to publish Easter dates decades in advance. Lunar festivals such as Diwali and Chinese New Year use the officially published dates for the years ahead.
Who makes this
DaysTo is built and maintained by FusionStudios, a Dutch web studio, and has been online since 2026. It is not a community project and not an anonymous template: one team writes the date rules, checks them against sources, and answers the mail. If a date here is wrong, that is on us, and hello@daysto.today reaches a person who can fix it.
Where the dates come from
The 68 countdowns on this site are not a typed-in list of dates. Each event carries a rule, and the rule produces the date for any year. Where a rule can be checked against an official publication, the countdown page names that publication and links to it. Where it cannot, the page says so in as many words rather than implying an authority that was never checked. A missing citation is a great deal better than a false one.
The sources used across the site are:
| Source | Used for |
|---|---|
| United Nations, list of international days | United Nations, UNESCO, WHO and FAO observance days. Thirteen dates were read off this list line by line and matched against what this site computes. |
| US Office of Personnel Management, federal holidays | Which days are United States federal holidays. The weekday rules behind the moving ones are set in 5 U.S.C. 6103. |
| NOAA NCEI, meteorological versus astronomical seasons | The split between meteorological seasons, which start on the first of March, June, September and December, and astronomical seasons, which start at the equinoxes and solstices. This site publishes both, on separate pages. |
| GOV.UK, UK bank holidays | Good Friday, Boxing Day and the early May bank holiday. |
Two conventions are ours rather than anyone else's, and both say so on their own pages: the back-to-school counter is anchored to mid-August because United States term dates are set district by district, and the equinox and solstice counters are anchored to the date the event falls on in almost every year of this century rather than to the exact drifting instant.
How we count a day
"How many days until" is ambiguous, so here is the answer this site gives. A day is a whole calendar day, and the count is the number of midnights between today and the target: today to tomorrow is one day, and the day of the event itself is zero, at which point the page says the event is today instead of showing a zero. The date calculator offers a checkbox to include the end day, because for a date range people genuinely mean it both ways.
The count uses your device's local calendar date, not our server's. A holiday is a date, not an instant: Christmas is 25 December wherever you are, so the target is resolved against your own midnight. The number rendered on our server is corrected in your browser the moment the page loads, which is why a visitor in Auckland and a visitor in Los Angeles both see a number that matches the calendar on their own wall.
When the dates were last checked
The event rules and their sources were last verified on 2026-08-05, and that date is shown on every countdown page. The intention is to recheck the coming year's dates each November and to log every correction in the changelog. Automated checks in the build already fail if any event resolves to a date in the past, and a regression test pins the dates for the next ten years so a refactor cannot move a holiday quietly.
Privacy
There are no accounts, no cookies for tracking, and no analytics that follow you. The site is static and the math happens on your device. You can use every tool offline once the page has loaded.
Last updated 2026-08-05. Dates verified on 2026-08-05.
Ready to count? Start with the age calculator or the date calculator.
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