The Business Days Planner compares built-in holiday calendars, shows the next common working day, and helps when a deadline spans more than one market.
Convert a date and time between cities and time zones. See local dates, UTC offsets, and practical scheduling context.
Calculate the exact difference between two dates in days, weeks, months, years, weekdays, and inclusive ranges.
Convert Unix timestamps in seconds or milliseconds to readable local and UTC dates, and generate the current timestamp.
A worked example showing how one 9:00 New York meeting changes across London, Madrid, Los Angeles, Dubai, Tokyo, and Sydney during 2026 daylight saving transitions.
Find out what day of the week it is today. Learn about the current day, day number, and how days of the week got their names.
Check the exact current time in your timezone. View time in 12-hour and 24-hour formats, UTC time, and learn about timezones.
See today's date in every format: ISO 8601, US, European, written, and more. Copy any date format to your clipboard instantly.
Find out the current ISO week number. Learn how week numbers are calculated and why they matter for business and planning.
View the current month calendar. See today highlighted, navigate between months, and keep track of upcoming dates.
See the current time in cities around the world. Compare time zones, track daylight saving changes, and plan across borders.
Find sunrise and sunset times for any supported city and date. See dawn, dusk, golden hour, and daylight duration.
Set a countdown timer for minutes, hours, or any custom duration. Features alerts, fullscreen mode, and popular preset times.
Free online stopwatch with lap timing, split times, and millisecond precision. Perfect for sports, cooking, and productivity.
Calculate legal, court, business, calendar-day, and SLA deadlines with holidays, cut-offs, audit trails, and exports.
Compare several cities, rank fair meeting slots, save shareable setups, and export calendar invites for distributed teams.
View public holidays by country and year, find the next holiday, inspect month coverage, and export CSV or ICS calendar files.
Work out your exact age in years, months and days, watch it tick live in seconds, and see your next birthday, the day you were born, Korean age, Chinese zodiac and life milestones.
Welcome to TodayDateAndTime.com, your go-to resource for accurate date and time information. Whether you need to quickly check today's date, verify the current time in your timezone, or look up the week number, we have you covered.
Keeping track of dates and times is essential in our interconnected world. From scheduling international meetings to filing deadlines, the accuracy of your date and time information matters. A useful date-and-time tool should give the answer quickly, but it should also show the context that prevents mistakes: time zone, UTC offset, week number, day of year, date format, and related tools when a simple lookup is not enough.
The way we measure time has evolved over centuries. The Gregorian calendar, introduced by Pope Gregory XIII in 1582, is now the most widely used civil calendar worldwide. It corrected the drift of the Julian calendar by refining the leap year rule, ensuring that our calendar stays aligned with Earth's orbit around the Sun. Today, international standards like ISO 8601 provide a universal format for representing dates and times, reducing confusion across borders and industries.
Live world timezone map — updates in real time to show where it is currently daytime (lighter) and nighttime (darker)
Time zones were formally adopted in the late 19th century to standardize timekeeping for railways and telecommunications. Before that, every town set its clocks to local solar time, which created chaos for scheduling. Today there are over 24 standard time zones, and many regions observe daylight saving time, shifting clocks forward in spring and back in autumn to make better use of daylight hours.
At the heart of modern timekeeping lies the atomic clock. The current international definition of a second is based on 9,192,631,770 oscillations of a cesium-133 atom. National metrology institutes around the world — including NIST in the United States, PTB in Germany, and NPL in the United Kingdom — maintain ensembles of these clocks. Their readings are combined by the Bureau International des Poids et Mesures (BIPM) in Paris to produce Coordinated Universal Time (UTC), the global reference from which every time zone is derived. The precision is extraordinary: the best optical lattice clocks today would neither gain nor lose a second in roughly 15 billion years, longer than the current age of the universe.
Beyond the basics, our site offers a suite of practical tools designed to work together. Use the World Clock to compare times across cities, the Time Zone Converter to translate a meeting time, the Countdown Timer to track upcoming events, or the Stopwatch for precise elapsed-time measurements. The Sunrise and Sunset calculator helps you plan outdoor activities by showing exact twilight phases and golden hour windows, while our Calendar view gives you a clear overview of the month ahead complete with historical events. The Week Number page is particularly useful for professionals who schedule by ISO week, and the date format display lets you copy today's date in any standard format with a single click.
The site is built around practical intent: checking the answer, copying it, comparing it, and knowing when a more specific calculator is needed. We also publish in-depth articles on our blog covering the history and science behind calendars, time zones, and timekeeping, so you can understand the stories behind the numbers.
Whether you are a traveler coordinating across time zones, a professional managing global teams, a developer working with timestamps, or simply curious about what day of the year it is, TodayDateAndTime.com is designed to give you fast, reliable answers. Bookmark this page and never wonder about the date or time again.
Current time in major cities around the world
The Gregorian reform skipped 10 calendar days in October 1582 to bring the calendar back into line with the seasons.
From our blog: history and science of calendars, clocks, and time zones
Why the days between two dates can have more than one correct answer—and a reliable method for inclusive dates, leap years, business days, deadlines, and DST.
February is short because of a Roman superstition about even numbers, a vanishing month called Mercedonius, and 2,000 years of nobody daring to touch it. The real history — and why the famous Augustus story is a myth.
By convention 12 PM is noon and 12 AM is midnight, but those are the two moments where the 12-hour clock breaks its own logic. Here is what AM and PM really mean, why they stumble, and how to write the time so nobody is confused.
Unix time is a single number counting seconds since 1970, and on January 19, 2038 the 32-bit version runs out. Here is what that means, why it already breaks things, and how it gets fixed.
A weekly 9:00 AM New York meeting does not stay at the same local time everywhere. This worked example shows the 2026 daylight saving gaps across London, Madrid, Los Angeles, Dubai, Tokyo, and Sydney.
We ran the same deadline rules through 10 national holiday calendars. A simple 10-business-day deadline spread from May 14 to May 19, and Christmas deadlines moved differently by country.
Because that is how long Earth takes to orbit the Sun: 365.2422 days, to be precise. The Gregorian calendar handles the leftover quarter-day with a leap-year rule — add a day every 4 years, skip every 100, but keep every 400. That gives an average year of 365.2425 days, which only drifts by one day every 3,236 years. So 2000 was a leap year, but 1900 and 2100 are not.
In theory, dividing 360° of longitude by 24 hours gives a 15°-wide zone for each hour. In practice, time zones follow politics, not geometry. China spans roughly 5 geographic zones but uses a single time (UTC+8) imposed by Beijing. India uses UTC+5:30, Nepal uses UTC+5:45, and the Chatham Islands use UTC+12:45. Including these half- and quarter-hour offsets, there are about 38 distinct standard offsets in use today.
UTC (Coordinated Universal Time) is the global reference, defined by an ensemble of about 450 atomic clocks at roughly 80 laboratories worldwide and coordinated by the BIPM in France. GMT (Greenwich Mean Time) is the historical British time zone based on the Sun crossing the meridian at the Royal Observatory in Greenwich. They agree to within a fraction of a second, but UTC is the modern, atomic-based standard. Your local time is simply UTC plus or minus your country's offset, possibly with daylight saving applied.
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC — a moment called "the Unix epoch." Because it is just an integer, it is timezone-independent, sorts naturally, and avoids the ambiguity of human-readable dates. Almost every database, log file, and API uses it under the hood. The 32-bit version of this counter will overflow on January 19, 2038 (the "Y2038 problem"), which is why modern systems store it as a 64-bit integer.
Daylight saving time (DST) shifts clocks one hour forward in spring and back in autumn so that more daylight falls in the evening hours during summer. It was first proposed by the New Zealand entomologist George Hudson in 1895 and first adopted nationally by the German Empire in April 1916 to save coal during the First World War. Today about 70 countries observe DST, mostly in Europe and North America. Its actual energy savings are small and disputed, and several jurisdictions are working to abolish it.
The seven-day week is one of the oldest continuously used units of time, dating back at least 4,000 years to the Babylonians, who linked each day to one of the seven celestial bodies visible to the naked eye: the Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn. The Romans inherited it, Christianity carried it across Europe, and Islam carried it across the Middle East and North Africa. Unlike the year and the month, the seven-day week has no astronomical basis — it just turned out to be too useful and too embedded in religious practice for any reform attempt to dislodge it.
The time displayed is your computer's clock, which on a modern machine is synchronized to within tens of milliseconds of UTC over the public internet using the Network Time Protocol (NTP), specified in RFC 5905. NTP servers themselves trace their accuracy back to atomic clocks at national metrology institutes. For everyday purposes — meetings, deadlines, schedules — that is far more precision than you will ever need.
ISO 8601 is the international standard for writing dates and times. Its core rule is to write the largest unit first: YYYY-MM-DD for dates, HH:MM:SS for times, separated by a "T" for combined timestamps (e.g., 2025-01-25T14:30:00Z). The format is unambiguous across cultures (03/04/05 means three different things in the US, Europe, and Japan), it sorts correctly as a plain string, and it is the format used by virtually every database, log file, and JSON API in the world.
Atomic clocks measure time by counting the oscillations of atoms — typically cesium-133, which vibrates exactly 9,192,631,770 times per second. This frequency is so stable that the best atomic clocks would not gain or lose a second in millions of years. These clocks are maintained by national laboratories worldwide and their outputs are averaged to produce UTC. Your phone and computer synchronize with these clocks through NTP servers, which is why the time on your screen is accurate to within a few milliseconds of the official global standard.
Most tools continue to be useful even on a weak connection once they have loaded. For privacy, personal inputs such as selected cities, dates, and timer values are not submitted to a server as part of the tool calculation.
Countries near the equator, such as most of Africa, Southeast Asia, and equatorial South America, see very little variation in daylight hours throughout the year, so shifting clocks would provide no meaningful benefit. Other countries, like Russia and China, have experimented with DST and abandoned it due to the confusion and economic disruption the clock changes caused. As of 2026, about 70 countries still observe DST, but several — including the European Union and various U.S. states — have ongoing legislative efforts to abolish it permanently.