Date and time tools that show their working
Ask how many days are left until a date and different sites give different numbers. Every answer here states the time zone it counted in and whether today counts, and lets you change both.
Time now, UTC
Friday, 7 August 2026 in UTC (GMT)
Time and zones
Dates and durations
- Date difference calculator Days, weeks and months between two dates
- Days from today The date N days before or after today
- Age calculator Years, months and days, to the second
- Day of the week Which weekday any date fell on
- Week number ISO week for any date
Countdowns and timers
- Countdown Days until any date, with the basis shown
- Christmas countdown Days until 25 December
- New Year countdown Days until 1 January
- Halloween countdown Days until 31 October
- Easter countdown Days until Easter Sunday
- Thanksgiving countdown Days until the fourth Thursday in November
- Valentine's Day countdown Days until 14 February
- Timer Counts down and alerts you
- Stopwatch Counts up, with laps
- Alarm clock Rings at a time you set
Calendars and holidays
- Calendar Every year from 1900 to 2100, printable 2026
- Public holidays Dates by country and year
- Religious holidays Easter, Ramadan, Passover, Diwali
Hours, formats and units
- Hours calculator Hours and minutes between two times
- Time unit converter Seconds to years, and back
- Unix timestamp converter Epoch seconds to a readable date 1786125038
Sun and moon
Why two sites answer the same question differently
On the day this was written, the pages ranking for one very ordinary question returned five different answers at the same moment: 139, 140, 141, 144 and 149 days. None of them said why.
The gap is not a bug in anyone's arithmetic. It is the time zone the count was made in and whether the current day was included. Both are legitimate choices and both change the number. What is missing everywhere else is the disclosure, and that is the thing this site is built around: the basis is printed under the answer on every page, and you can change it.
Questions
Why do date calculators disagree about how many days are left?
Two reasons, and they compound. The first is the time zone: it is already tomorrow in Auckland while it is still today in Los Angeles, so the same question has two correct answers at the same instant. The second is the counting basis: some tools count today as day one and some do not, which shifts every result by exactly one. DateTools states both under every answer and lets you change either.
What is the difference between inclusive and exclusive counting?
Exclusive counting excludes the start day, so Tuesday to Friday is three days. Inclusive counting counts the start day, so the same gap reads as four days. Neither is wrong. Payroll and notice periods usually count inclusively, while everyday questions like how many days until Christmas usually count exclusively. DateTools defaults to exclusive and shows you which is in force.
Which time zone data does DateTools use?
The IANA time zone database, read through your browser rather than bundled with the page. That means daylight saving rule changes reach you as soon as your browser updates, with no wait for us to redeploy, and it means we ship no duplicate copy of the database.
Do the tools work without JavaScript?
The answer, the prose and the reference tables are in the HTML and render without JavaScript. Live updating, the ticking clock and recalculating when you change an input need JavaScript. Every result also has its own permanent web address, so an answer can be linked to, indexed and quoted.