Count how many days are left until any date.
Pick a future date and this tool returns how many days remain, broken down into weeks and into years, months and days. It counts from today to the target date, so a date tomorrow returns 1 and today returns 0.
That inclusivity question is where most disagreements about date arithmetic come from. There are two defensible answers to "how many days from Monday to Friday": four, which is the number of nights or the elapsed duration, and five, which is the number of days involved if you count both endpoints. This tool reports elapsed days, the same convention your calendar app uses. If you are counting something like days of annual leave, where both the first and last day are consumed, add one.
Counting from 6 August 2026 to 25 December 2026:
Days and weeks are fixed units. Months are not — they run from 28 to 31 days, so "three months from now" has no single correct answer. The convention almost everyone uses, and the one applied here, is to keep the same day number and move the month forward, falling back to the last valid day when it does not exist. That is what makes 31 January plus one month equal 28 February in a normal year, and it is also why the operation is not reversible: 28 February minus one month gives 28 January, not 31 January.
Because of this, a breakdown like "4 months and 12 days" is precise only in combination with the start date. The plain day count is the figure to use for anything that has to be exact, such as an interest calculation or a legal deadline.
A year is a leap year if it is divisible by 4, except that century years must also be divisible by 400. So 2024 and 2028 are leap years, 1900 was not, and 2000 was. Any countdown spanning a 29 February picks up that extra day automatically. The rule exists because the Earth's orbital period is about 365.2422 days; a plain four-year rule overcorrects slightly, and the 400-year exception brings the calendar back to within about one day in 3,200 years.
| Question | Use |
|---|---|
| How long until a future date? | This tool |
| How many days between two arbitrary dates? | Date difference calculator |
| How old is someone today? | Age calculator |
This counts every day, including weekends and public holidays. For a project deadline you usually want business days instead. As a quick approximation, multiply calendar days by 5/7 and then subtract public holidays: 141 calendar days is roughly 100 working days before holidays. The approximation drifts by up to two days depending on which weekday you start from, so for a contractual deadline count the actual weeks and add the remainder by hand.
It is also worth checking which convention a contract uses. "Within 30 days" almost always means calendar days, while "within 30 business days" is more than six weeks. Some jurisdictions also define whether the day of the triggering event counts as day zero or day one, which shifts every subsequent date by one.
The calculation uses your device's local date. If you are counting toward an event in another time zone, the answer can be out by one near midnight — a deadline of "31 December" in New York is already past for someone in Tokyo well before their own new year. For anything where a single day matters, work out the deadline in the relevant time zone first and count to that local date.
No. It counts elapsed days from today to the target, so tomorrow returns 1 and today returns 0. If you need both endpoints counted — as with days of leave, where the first and last day are both used — add one to the result.
No, every calendar day is counted. For working days, multiply by 5/7 as a rough guide and subtract public holidays, or count the weeks directly if the deadline is contractual.
Automatically. Any period spanning 29 February includes it. A leap year is one divisible by 4, unless it is a century year not divisible by 400 — so 1900 was not a leap year but 2000 was.
Because months vary from 28 to 31 days, so a month is not a fixed quantity. The breakdown keeps the day number and advances the month, clamping to the last valid day where needed. For anything that must be exact, use the plain day count.
Use the date difference calculator for that — it handles two arbitrary dates in either direction and reports the elapsed time between them.