A time converter changes a value from one time unit to another by scaling it through seconds: result = value × (seconds in source ÷ seconds in target). There are 60 seconds in a minute, 3,600 in an hour, 86,400 in a day and 31,556,952 in an average year. This platform converts all 12 units instantly, plus world time zones, meeting overlaps, date differences, countdowns, timestamps and business hours — accurately and privately in your browser.
Key Takeaways
- Time conversion scales a value by the ratio of unit sizes: result = value × (seconds in source ÷ seconds in target).
- There are 60 seconds in a minute, 3,600 in an hour, 86,400 in a day, 604,800 in a week and 31,556,952 in an average year.
- Months and years vary in length, so this tool uses astronomical averages (1 year = 365.2425 days) for unit conversion and exact calendar math for date differences.
- UTC is the global time standard; GMT is a time zone that usually equals UTC. Local times are UTC plus or minus an offset.
- Daylight Saving Time shifts a region’s clock (usually +1 hour) for part of the year, changing its UTC offset and time differences.
- Unix time counts the seconds elapsed since 1 January 1970 UTC, ignoring leap seconds — the backbone of timestamps in software.
Time Reference Library
Fixed units
- 1 minute
- 60 seconds
- 1 hour
- 60 min · 3,600 s
- 1 day
- 24 h · 1,440 min · 86,400 s
- 1 week
- 7 days · 168 h · 604,800 s
Calendar units
- 1 month (avg)
- 30.44 days · 730.5 h
- 1 year (avg)
- 365.2425 days · 8,766 h
- 1 common year
- 365 days · 31,536,000 s
- 1 leap year
- 366 days · 31,622,400 s
- 1 decade
- 10 years · ~3,652 days
- 1 century
- 100 years · ~36,524 days
Business units
- 1 business day
- 8 hours
- 1 working week
- 40 hours · 5 days
- 1 work year
- ~2,080 hours · 52 weeks
- 1 sprint
- 2 weeks · 14 days
- 1 academic hour
- 45–50 minutes
Sub-second & scientific
- 1 millisecond
- 0.001 s · 1,000 µs
- 1 microsecond
- 0.000001 s · 1,000 ns
- 1 nanosecond
- 0.000000001 s
- 1 Unix epoch
- 1 Jan 1970, 00:00 UTC
People Also Ask
How do I convert time units?
Enter a value and its unit, then pick the target unit. The converter multiplies by the ratio of the two units’ sizes in seconds. For example, 2 hours × (3,600 s ÷ 60 s) = 120 minutes.
How many seconds are in a day?
There are 86,400 seconds in a day (24 hours × 60 minutes × 60 seconds). A week has 604,800 seconds and an average year has 31,556,952 seconds.
What is the difference between UTC and GMT?
UTC (Coordinated Universal Time) is the modern atomic time standard used worldwide. GMT (Greenwich Mean Time) is a time zone that is normally equal to UTC. In everyday use they are interchangeable; in science UTC is the precise reference.
How do time zones work?
Each region’s local time is UTC plus or minus a fixed offset, in whole or half hours. As you move east the local time gets later; west, earlier. Daylight Saving Time temporarily changes a region’s offset.
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have passed since midnight UTC on 1 January 1970 (the Unix epoch). It is a timezone-independent way to store an exact instant, widely used by programmers and APIs.
How do I find the best meeting time across time zones?
Enter each participant’s time zone and working hours. The meeting planner overlays everyone’s availability and highlights the hours when all participants are within their working day.
Popular Time Conversions
What Is Time Conversion?
Time conversion is the process of expressing a quantity of time in a different unit while keeping its real value the same. When you say that two hours is the same as 120 minutes, or that a project will take 90 days rather than three months, you are converting time. It sounds trivial, but it underpins an enormous amount of everyday and professional work — from scheduling and billing to scientific measurement and software engineering — and small mistakes can have outsized consequences.
Every time conversion works by passing through a common base unit. In this tool, and in most computing, that base is the second. To convert two hours into minutes, the tool first works out how many seconds two hours contains (7,200), then divides by the number of seconds in a minute (60) to get 120. The same machinery converts nanoseconds to centuries and everything in between. Because the base is consistent, you can chain any two units together without ambiguity.
The one subtlety is that not all units are fixed. A second, minute, hour, day and week always contain the same number of seconds, so their conversions are exact. Months and years, however, vary: a month can be 28 to 31 days and a year 365 or 366. To keep conversions honest, this platform uses precise astronomical averages for the variable units, while offering separate, fully calendar-aware tools for measuring the exact gap between two real dates.
Time Units Explained
The familiar ladder of time units climbs from the almost imperceptible to the vast. At the small end sit the nanosecond (a billionth of a second), microsecond (a millionth) and millisecond (a thousandth), which matter in computing, telecommunications and physics. The second is the internationally defined base unit of time, formally measured by the vibrations of a caesium atom. From there we step up to the minute (60 seconds) and the hour (60 minutes).
Above the hour, units become tied to the natural world. A day — 24 hours — is one rotation of the Earth. A week of seven days is a human convention with ancient astronomical and religious roots. A month approximates a lunar cycle, and a year — about 365.24 days — is one orbit of the Earth around the Sun. Because these astronomical periods do not divide evenly, calendars use leap days and varying month lengths to stay aligned, which is why months and years are “average” units in conversion.
At the large end, a decade is ten years, a century one hundred, and a millennium one thousand. Alongside these natural and conventional units sit purpose-built business units: the eight-hour business day, the forty-hour working week, the academic hour of forty-five to fifty minutes, and accounting periods such as fiscal quarters and years. Understanding which kind of unit you are dealing with — fixed, astronomical or business — is the key to converting time correctly.
Seconds, Minutes and Hours
The relationship between seconds, minutes and hours is the foundation of everyday timekeeping, and it is built on the number 60. There are 60 seconds in a minute and 60 minutes in an hour, giving 3,600 seconds in an hour. This base-60, or sexagesimal, system was inherited from the ancient Babylonians, who favoured 60 because it divides neatly by many numbers — 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30 — making fractions of an hour easy to express.
Converting between these units is pure multiplication and division. To turn hours into minutes, multiply by 60; to turn minutes into seconds, multiply by 60 again. Going the other way, divide. So 2.5 hours is 150 minutes or 9,000 seconds, and 5,400 seconds is 90 minutes or 1.5 hours. These conversions are exact and unaffected by calendars, leap years or time zones, which makes them the safest and most common time calculations.
These small units carry surprising weight in practice. Billing is often done in minutes or six-minute tenths of an hour; athletic performance is measured to hundredths of a second; and computer systems schedule work in milliseconds. Being fluent in second-minute-hour conversion — and letting a tool handle the arithmetic for awkward values — prevents the rounding errors that quietly accumulate in timesheets, invoices and schedules.
Hours, Days and Weeks
Stepping up from hours, a day contains 24 hours, or 1,440 minutes, or 86,400 seconds. A week contains 7 days, which is 168 hours or 10,080 minutes. These conversions are exact because, for the purposes of arithmetic, every day is treated as 24 hours and every week as 7 days. The only practical wrinkle is Daylight Saving Time, which makes one local day a year 23 hours and another 25 hours — but the underlying day is still 24 hours of elapsed time.
These units dominate planning. Projects are scoped in days and weeks, leave is counted in days, and working time is organised around the week. Converting fluently between them helps you sanity-check estimates: a “six-week” task is 42 days or about 1,008 hours of calendar time, though only a fraction of that is working time. Confusing calendar time with working time is one of the most common scheduling errors, which is why this platform separates the two.
When you need the exact number of days or hours between two specific dates — say, the working days until a deadline — averages are not enough, because months differ in length and weekends and holidays intervene. For those questions, the Difference and Business tabs count the real calendar, while the unit converter handles the clean “how many hours in three weeks” style of question instantly.
Weeks, Months and Years
Once you climb above the week, time units stop dividing evenly and conversions become approximate. A month averages about 30.44 days — one twelfth of the average year — but real months range from 28 to 31 days. A year averages 365.2425 days under the Gregorian calendar, but any individual year is 365 or 366. There are about 4.35 weeks in an average month and 52.18 weeks in a year, not the round “4 weeks” and “52 weeks” often assumed.
These averages exist because the Earth’s orbit does not contain a whole number of days. A solar year is roughly 365.2422 days, and the Gregorian calendar approximates this with its leap-year rule, producing an average of 365.2425 days. Using these precise averages, rather than rough round numbers, keeps long-range conversions accurate: converting 18 months to days as 18 × 30.44 ≈ 548 days is far closer to reality than 18 × 30 = 540.
For everyday questions like “how many days is six months?” the average is the right tool, and this converter applies it automatically. But for contracts, ages and deadlines that hinge on actual calendar dates, you should count the real days between the two dates — including any 29 February — using the Difference tab. Knowing when to use an average and when to count exactly is the mark of careful time math.
Time Zones Explained
A time zone is a region of the Earth that keeps a uniform standard time, defined as a fixed offset from Coordinated Universal Time (UTC). The system exists because the Earth rotates, so noon — when the sun is highest — happens at different moments around the globe. Rather than every town keeping its own solar time, the world is divided into zones, each shifting its clocks by a set amount so that local time stays roughly in step with the sun.
Most zones are offset from UTC by a whole number of hours, from UTC−12 to UTC+14, but several use half-hour or even 45-minute offsets — India is UTC+5:30, and Nepal is UTC+5:45. Offsets generally increase as you travel east and decrease as you travel west. The International Date Line, near the 180° meridian, is where the calendar date flips, so two places can share a clock time yet be a day apart.
In software, time zones are managed through the IANA time zone database, a meticulously maintained record of every region’s offset and Daylight Saving rules, past and present. This platform uses that database through your browser, so the world clock, converter and meeting planner always apply the correct offset and DST status for any region and date — including historical quirks and recent rule changes — without you having to look anything up.
UTC vs GMT
UTC and GMT are often used interchangeably, and in daily life that is harmless, but they are not quite the same thing. GMT, Greenwich Mean Time, is mean solar time at the Royal Observatory in Greenwich — a time zone rooted in the position of the sun. UTC, Coordinated Universal Time, is a modern time standard based on a global network of atomic clocks, kept deliberately close to mean solar time but defined by physics rather than the sky.
The practical differences are subtle. UTC never changes for Daylight Saving Time and is the precise reference used in science, aviation, computing and international coordination. The GMT zone, as observed in the United Kingdom, applies in winter but gives way to British Summer Time (UTC+1) in summer. UTC is also occasionally adjusted by a leap second to stay aligned with the Earth’s gradually slowing rotation, whereas GMT, as a solar concept, needs no such correction.
For everyday purposes you can treat 12:00 GMT and 12:00 UTC as the same instant. When precision matters — timestamping transactions, coordinating a global launch, or writing software — UTC is the correct standard to specify, because it is unambiguous and free of DST. This platform uses UTC as its neutral anchor and converts to any local zone from there.
Daylight Saving Time Explained
Daylight Saving Time (DST) is the seasonal practice of moving clocks forward, usually by one hour, so that daylight extends later into the evening during the warmer months. Clocks “spring forward” in spring and “fall back” in autumn. The aim is to make better use of natural light and, historically, to save energy — though the modern energy savings are debated, and many regions have considered abolishing the practice.
DST has real consequences for time math. When a region is on DST, its UTC offset increases, so the time difference with other places changes. Because countries start and end DST on different dates — or do not observe it at all — the gap between two cities can shift several times a year. The transitions themselves create oddities: one local day loses an hour (a 23-hour day) and another gains one (a 25-hour day), and a clock time can be skipped or repeated.
These complications are exactly why you should never compute time-zone differences by hand from memory. This platform reads live DST rules from the time zone database, so the world clock shows whether each zone is currently observing DST, and the converter and meeting planner always use the correct offset for the chosen date. That removes a whole class of scheduling errors, especially around the spring and autumn changeovers.
Unix Timestamp Guide
A Unix timestamp is a single number that pinpoints an exact instant in time: the count of seconds since the Unix epoch, midnight UTC on 1 January 1970. Because it is just a number, free of time-zone and formatting ambiguity, it has become the lingua franca of computing. Databases, APIs, log files and programming languages overwhelmingly store and exchange time as Unix timestamps, converting to human-readable dates only for display.
Timestamps come in a few resolutions. The classic Unix timestamp counts whole seconds; many systems use milliseconds (multiplying by 1,000) for finer granularity, and some use microseconds or nanoseconds. Converting a timestamp to a date means interpreting that count from the epoch; converting a date to a timestamp means counting the seconds back to 1970. Crucially, Unix time ignores leap seconds, trading a tiny inaccuracy for arithmetic that is simple and reliable.
The Developer toolkit here converts freely between Unix timestamps (in seconds or milliseconds), ISO 8601 and RFC 3339 strings, and human-readable local and UTC dates. It is built for the practical tasks programmers face every day: reading a timestamp from a log, generating one for an API call, or sanity-checking why a date is eleven hours off because someone forgot a time zone. The Year 2038 limit of 32-bit timestamps is also worth knowing when working with older systems.
Business Time Calculations
Business time is different from calendar time, and conflating the two is a costly mistake. A working day is typically eight hours, a working week forty, and a working year — after weekends, public holidays and leave — far short of the 8,760 hours in a calendar year. Payroll, billing, capacity planning and service-level agreements all depend on counting working time correctly, with its own units and rules.
The core business calculations are straightforward once defined. Daily hours are the span from clock-in to clock-out, minus unpaid breaks. Overtime is the portion beyond a threshold — commonly eight hours a day or forty a week — paid at a premium such as 1.5×. Billable hours track client-facing work, often in tenths of an hour. Shift work adds night and weekend differentials. The Business tab turns your start time, end time, break and rates into regular hours, overtime and pay in one step.
Getting these numbers right matters for fairness and compliance as much as for accounting. Underestimating overtime can breach labour law; overestimating capacity leads to missed deadlines. By computing working hours explicitly — rather than guessing from calendar spans — teams build realistic schedules, invoice accurately and treat staff fairly. This platform keeps business units distinct from astronomical ones precisely so these calculations stay honest.
Project Time Management
Time is the currency of project management, and converting between its forms is a daily task. Estimates arrive in hours of effort, schedules are drawn in calendar days and weeks, and progress is tracked against deadlines. A plan that confuses effort hours with calendar time — assuming forty hours of work fits into one calendar week of elapsed time regardless of meetings, dependencies and holidays — is a plan that slips.
Agile teams add their own time-boxes. A sprint is usually two weeks; releases are planned in sprints; and roadmaps span quarters. Converting between these — how many working days are in a two-week sprint, how many sprints fit before a quarter-end deadline — keeps commitments realistic. The duration and difference tools here let you add a sprint to a start date, count the working days to a milestone, or see exactly how far away a deadline is in days, hours and minutes.
Good project time management also means communicating time unambiguously across a distributed team. A deadline of “end of Friday” means different instants in San Francisco, London and Singapore. Stating deadlines in UTC, and using a meeting planner to find genuine overlap, removes the ambiguity that derails handoffs. The countdown and meeting tools on this page are designed to support exactly this kind of disciplined, time-zone-aware planning.
Remote Team Scheduling
As teams spread across continents, scheduling becomes a time-zone problem before it is a calendar problem. The central challenge is finding hours when everyone is awake, available and within their working day. With colleagues in, say, San Francisco, London and Bangalore, the overlap can be just an hour or two — and missing it means someone joins a call at dawn or midnight, week after week.
A meeting planner solves this by overlaying each participant’s local working hours and highlighting the windows where they all coincide. Instead of mentally juggling offsets and Daylight Saving changes, you see at a glance which UTC hours work for the whole group. This platform’s planner does exactly that, accounting for half-hour offsets and current DST status, so the suggested slots are genuinely fair and correct.
Beyond live meetings, healthy remote scheduling leans on asynchronous work, clear “core hours” of expected overlap, and rotating inconvenient meeting times so the same person is not always sacrificing their evening. Tools that make time differences visible — a multi-zone world clock and an overlap finder — turn an abstract source of friction into a concrete, solvable scheduling task, which is why they sit at the heart of this platform.
Travel Time Planning
Travel scrambles time in ways that catch even experienced travellers out. The key insight is that flight duration is elapsed time, not the difference between the clock readings at departure and arrival. A flight leaving New York at 22:00 and landing in London at 10:00 has not taken twelve hours — once you account for the five-hour time difference, the real duration is about seven hours. Converting both times to UTC and subtracting gives the true figure.
Time zones also shape arrival planning, layovers and jet lag. Crossing multiple zones, especially eastward, disrupts the body clock; a common rule of thumb is roughly one day of adjustment per zone crossed. Knowing the local arrival time, the offset from home, and the number of zones traversed helps you plan sleep, meetings and connections sensibly rather than arriving disoriented and over-scheduled.
The Aviation tab on this platform computes real flight duration from local departure and arrival times and zones, flags whether the journey crosses midnight, and estimates jet-lag severity from the zones crossed. Combined with the world clock and converter, it turns the confusing arithmetic of international travel into clear numbers, so you can plan itineraries, ground transport and that first crucial meeting with confidence.
Scientific Time Measurement
Science demands a far more rigorous definition of time than calendars provide. Since 1967, the second has been defined not by the Earth’s motion but by atomic physics: one second is the time for 9,192,631,770 oscillations of the radiation emitted by a caesium-133 atom. Atomic clocks realising this definition are so stable they would drift by less than a second over hundreds of millions of years, and they form the basis of UTC.
At the small scale, scientific and engineering work routinely uses milliseconds, microseconds, nanoseconds and even picoseconds and femtoseconds. Light travels about thirty centimetres in a nanosecond, processor cycles are measured in nanoseconds, and laser pulses in femtoseconds. Converting cleanly between these sub-second units — and up to human scales — is essential in fields from telecommunications to particle physics, where a microsecond can be the difference between a measurement and an error.
Because the Earth’s rotation is gradually and irregularly slowing, atomic time (UTC) is kept aligned with astronomical time by the occasional insertion of a leap second. This reconciles the precise, physics-based second with the messy reality of a spinning planet. This converter uses the modern fixed-length second for all its arithmetic, which is exactly what virtually all scientific, engineering and computing work requires.
History of Timekeeping
Humanity has measured time for millennia, beginning with the sky. The earliest timekeepers read the sun with shadow clocks and sundials, and the moon to mark months. Ancient Egyptians divided daylight and darkness into twelve parts each, giving us the 24-hour day, while the Babylonians’ base-60 mathematics bequeathed the 60-minute hour and 60-second minute that we still use today.
Mechanical innovation steadily sharpened our grip on time. Water clocks and candle clocks gave way to the weight-driven mechanical clocks of medieval Europe, and then to the pendulum clock in the seventeenth century, which for the first time kept time to within seconds a day. The marine chronometer solved the longitude problem for navigation, and by the nineteenth century, railways forced the standardisation of local times into the time zones we recognise now.
The twentieth century moved timekeeping from the mechanical to the atomic. Quartz clocks, regulated by the vibration of a crystal, brought cheap precision to wrists and walls, and atomic clocks redefined the second itself in 1967. Today, satellite navigation, financial markets and the internet all depend on atomic time distributed worldwide. The long arc from sundial to atomic clock is a story of ever-greater precision — the same precision this platform puts at your fingertips.
Calendar Systems
A calendar is a system for organising days into longer units like weeks, months and years, and humanity has devised many. The challenge they all wrestle with is that the natural cycles — the day, the lunar month of about 29.5 days, and the solar year of about 365.24 days — do not divide evenly into one another. Every calendar is a different compromise for keeping human dates aligned with the sun, the moon, or both.
The Gregorian calendar, used by most of the world today, is a solar calendar introduced in 1582 to correct a small drift in the older Julian calendar. Its refined leap-year rule — a leap day in years divisible by four, except century years not divisible by four hundred — keeps the average year at 365.2425 days, very close to the true solar year. Other systems remain in wide use: the Islamic calendar is purely lunar, the Hebrew and many Asian calendars are lunisolar, and several cultures maintain their own era counts.
These differences matter whenever dates cross cultural or historical boundaries — converting a historical date recorded under the Julian calendar, or aligning a religious lunar date with the Gregorian one. While this platform works in the Gregorian calendar that dominates modern commerce and computing, understanding that calendars are human constructs, each with its own rules, helps explain why date math can be surprisingly intricate.
Common Time Formulas
A handful of formulas cover most time calculations. The master conversion formula is: result = value × (seconds per source unit ÷ seconds per target unit). Everything else follows from the fixed ratios — 60 seconds per minute, 60 minutes per hour, 24 hours per day, 7 days per week — and the averages of 30.44 days per month and 365.2425 days per year for the variable units.
For exact calendar work, the formulas shift from multiplication to counting. The number of days between two dates is the difference in their day-counts; age is that difference expressed in years, months and days with a check for whether the birthday has passed. A Unix timestamp is the seconds between an instant and 1 January 1970 UTC, and local time is UTC plus the zone’s offset, adjusted for Daylight Saving when active.
Working-time formulas add thresholds and rates: daily hours are the worked span minus breaks; overtime is hours beyond the daily or weekly threshold, paid at a multiplier; and annual working hours are roughly weekly hours times working weeks. Rather than memorise all of these, you can let this platform apply the right formula automatically — but knowing the underlying relationships lets you sanity-check any result and understand exactly what the tool is computing.
Time, Scheduling and Productivity
Beyond raw conversion, understanding time is a productivity skill. Techniques like time-boxing — assigning a fixed duration to a task — and the Pomodoro method of focused intervals separated by short breaks rely on accurate, deliberate use of minutes and hours. Converting effort estimates into realistic calendar schedules, and protecting blocks of deep-work time across a distributed team, turns good intentions into delivered work.
Countdowns and timers are simple but powerful productivity aids. A visible countdown to a deadline creates healthy urgency and keeps long-range goals salient; a timer enforces focus and breaks. The stopwatch, timer and countdown modules on this platform are designed not just as gadgets but as practical tools for managing attention, meeting deadlines and measuring how long work actually takes — data that makes future estimates more accurate.
The deeper point is that time, unlike money, cannot be earned back, so converting and planning it carefully is a high-leverage habit. Whether you are billing clients, coordinating across zones, planning a project, or simply trying to make a meeting work for everyone, a clear grasp of time units, zones and durations — supported by reliable tools — lets you spend this finite resource with intent rather than by accident.
Real-World Examples
Consider a freelancer billing a client for a 90-minute call and a task that took 2 hours 15 minutes. Converting to decimal hours — 1.5 and 2.25 — and summing gives 3.75 billable hours, which at an hourly rate is straightforward to invoice. Doing this in their head as “three and three-quarter hours” avoids the common error of treating 75 minutes as 0.75 of an hour, and a converter removes the risk entirely.
Or take a product team launching globally at “midnight UTC”. In San Francisco that is 4 pm or 5 pm the previous day depending on DST; in London it is midnight or 1 am; in Sydney it is the next morning. Stating the launch in UTC and using a world clock to translate it for each office means everyone shows up at the right moment, and the countdown timer keeps the whole company synchronised to the same instant.
Finally, imagine planning a trip from Delhi to New York: a flight departing 02:00 IST and arriving 07:30 EST. The clocks suggest five and a half hours, but with India 9.5 hours ahead, the real flight is about fifteen hours, crossing midnight and many time zones — a recipe for significant jet lag. Computing the true duration and arrival context in advance lets the traveller plan sleep and that first meeting realistically. These everyday situations show why understanding time, not just reading a clock, protects real money, plans and wellbeing.
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Frequently Asked Questions
How does a time converter work?
How many seconds are in a minute?
How many seconds are in an hour?
How many seconds are in a day?
How many hours are in a day?
How many hours are in a week?
How many days are in a week?
How many days are in a month?
How many days are in a year?
How many weeks are in a year?
How many minutes are in a day?
How many seconds are in a year?
What is UTC?
What is GMT?
What is the difference between UTC and GMT?
How do time zones work?
How many time zones are there?
What is DST?
Why does DST affect time differences?
What is a leap year?
What is a leap second?
What is Unix time?
What is the Unix epoch?
What is the Year 2038 problem?
How do I convert a timestamp to a date?
What is ISO 8601?
What is RFC 3339?
How do I calculate the difference between two dates?
How do I add or subtract time from a date?
How many working hours are in a year?
How do I calculate overtime?
How do I find a good meeting time across time zones?
How do I calculate flight duration across time zones?
What causes jet lag?
How many milliseconds are in a second?
What is a nanosecond?
What is a decade, century and millennium?
Why do months and years vary in length?
What is the most accurate way to convert months to days?
What is a fiscal year?
What is a business day?
How many weeks are in a month?
How accurate is this time converter?
Does this tool handle Daylight Saving Time?
Does the converter store my data?
Can I convert thousands of values at once?
How do I create a countdown to an event?
What is the difference between a stopwatch and a timer?
What is IST and how does it relate to UTC?
What is EST and EDT?
What is the time difference between India and New York?
Why is the international date line important?
What is the 24-hour clock?
How do I convert 12-hour time to 24-hour time?
What is the Julian calendar versus the Gregorian calendar?
How long is a sprint in project management?
How do I calculate someone’s age?
What is an academic hour?
How do I export or share my results?
Is this time converter free?
What time zone does the tool use by default?
Can I plan around half-hour and 45-minute time zones?
Built by the Omnitool Tools Team
Our editors build and maintain precision calculators used for millions of conversions a month, with a focus on accuracy and clear methodology.
IANA time zone database
Time zone, DST and meeting calculations use the official IANA tz database through your browser, so offsets and daylight-saving rules are always current and correct.
Last updated June 2026
Unit ratios use Gregorian averages (1 year = 365.2425 days); date math uses full calendar logic including leap years. Content is reviewed regularly.
Accuracy note: Fixed units (seconds through weeks) convert exactly; months, years, decades and centuries use astronomical averages, so for exact spans between real calendar dates use the Difference or Duration tabs. Time zone and DST data come from your device’s time zone database. All calculations run privately in your browser — your history, saved zones and countdowns never leave your device.
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