Today’s date and time

The date and time at the top of this page come from four separate things: a count of seconds kept by atomic clocks, the rules of your time zone, the calendar that turns days into dates, and the conventions for writing it all down. Each can go wrong in its own way.

The instant: UTC and the clocks behind it

Every clock on Earth is ultimately set from Coordinated Universal Time, UTC. UTC is computed from a worldwide set of atomic clocks by the International Bureau of Weights and Measures. National laboratories such as NIST and the US Naval Observatory each keep a real-time version of it; NIST says the two US versions typically agree to within 20 nanoseconds. Phones and computers pick up that time over the internet with the Network Time Protocol, or from mobile networks and GPS, and usually stay within a fraction of a second of it.

Many devices drift, though, and some are minutes off. A web page can only read the clock of the device it runs on. So when this page opens, it asks our server, which is synchronised to UTC, for the time up to five times. It measures each round trip and keeps the fastest. That bounds the error to half the round trip, usually a few hundredths of a second. The line under the clock tells you how far your own device is off. UTC itself is about to change: from 20 May 2027 it will run without leap seconds.

The time zone: from UTC to your local time

Local time is UTC plus an offset set by law in each country or region. New York is UTC−5 in winter and UTC−4 in summer. India is UTC+5:30 all year. Nepal is UTC+5:45. The rules, past and present, are collected in the IANA time zone database, which every major operating system uses. It holds 312 geographic zones, and 101 of them change their clocks for daylight saving time.

The database is updated several times a year as governments change their rules; 2026 alone brought six releases. Browsers carry their own copy, which can be months old, so this site ships the current release (2026f) itself and uses it in place of the browser’s. How we keep time lists the 2026 changes that older browsers get wrong.

Abbreviations are the weak point of time zones. EST means UTC−5, but New York uses EDT, UTC−4, for most of the year, so “EST” in July is usually a mistake for “Eastern Time”. IST can mean India, Israel or Irish Standard Time, and CST can mean US Central, China or Cuba. When an abbreviation could be read two ways, this site says which meaning it uses. Pages about a place use the place’s zone name, such as America/New_York, which is never ambiguous.

The date: midnight, the date line and the calendar

Today’s date depends on where you are, because it changes at local midnight. Kiritimati, Kiribati, at UTC+14, reaches a new date first and Niue, at UTC−11, last, so for 1 hour each day three dates are in use on Earth at once (where tomorrow has already begun). That is why a date on this page is always worked out for a specific zone, yours unless the page is about somewhere else, and why it changes at your midnight with the page still open.

Dates are counted in the Gregorian calendar, introduced in 1582 and used almost everywhere for civil life. Its rule of 97 leap days in every 400 years keeps the year within half a minute of the seasons on average. Leap years and the Gregorian calendar explain the details, including the ten dates skipped in October 1582. The weekday comes from an unbroken seven-day cycle. Astronomers count days continuously with the Julian Day Number, and its remainder after dividing by 7 gives the weekday of any date in any era. This site works out every date the same way.

Weeks and day numbers

Week numbers come in two main systems. ISO 8601 starts weeks on Monday and counts from the week that contains the year’s first Thursday; the US convention starts them on Sunday and counts from the week that contains January 1. The two often differ by one, which is why “Today at a glance” shows both, and weeks in a year explains why some years have 53. The day of the year runs from 1 to 365, or 366 in a leap year. Logistics and military systems write it as a five-digit “Julian date” (YYDDD), which has nothing to do with the astronomers’ Julian Day count; Julian date converts both.

Writing it down

A date such as 02/11 means February 11 in the United States and 2 November in most other countries. Writing the year first (the ISO 8601 order, 2026-11-02) or the month as a word removes the doubt, and year-first dates also sort correctly as text. Date formats shows today in every common format and which countries use which order.

Other calendars

Many people also live by another calendar. The Islamic (Hijri) calendar is lunar, with months of 29 or 30 days and a year of 354 or 355 days, so its dates move through the seasons. The date shown here follows Saudi Arabia’s Umm al-Qura calendar as computed by the Unicode ICU library. Where the new month starts with the sighting of the crescent moon, the local date can differ by a day. Japan numbers years by era, and 2026 is Reiwa 8. Some churches still keep the Julian calendar for feast days; it currently runs 13 days behind the Gregorian, so their Christmas falls on January 7.

Questions

What day is it today?

The first line of this page answers it: the weekday, then the date, for the time zone your device is set to. It changes at your local midnight, also while the page stays open. For the date somewhere else, type the place into the box at the top.

What year is it?

The year is the last part of the date line at the top, worked out for your own time zone. On December 31 and January 1, people in different time zones can briefly be in different years: when the new year has begun in Sydney it is still the old year in New York.

What is today’s date in numbers?

In the US, month first (MM/DD/YYYY). In most other countries, day first (DD/MM/YYYY). In the ISO 8601 international format, year first (YYYY-MM-DD). “Today in numbers” on this page shows all three for today with copy buttons, and every format lists about 30 more.

Why does someone else have a different date?

A date is local. It changes at midnight in each time zone, so at every moment at least two dates are in use around the world, and for one hour each day three. Tokyo, for example, is a calendar day ahead of New York from 10 a.m. New York time in winter (11 a.m. in summer) until New York’s midnight.

What week is it?

Under ISO 8601, which most of Europe and international business use, weeks start on Monday and week 1 is the week containing the year’s first Thursday. In the US convention, weeks start on Sunday and week 1 is the week containing January 1, so the two numbers can differ by one. Both are shown in “Today at a glance”.

How accurate is the clock on this page?

It is checked against our server, which is synchronised to UTC, when the page opens and every 15 minutes. Your browser measures each round trip and keeps the fastest, so the error is at most half that round trip, usually a few hundredths of a second. The line under the clock says whether your device is fast or slow. How we keep time explains the method.

Why is the time zone shown not mine?

The page uses the time zone your device reports. If it is wrong, the device’s own setting is wrong too; fix it in the date and time settings, ideally with “set automatically” switched on. A VPN does not change it, but a manually chosen zone does.