Free Date, Age and Time Calculators Online

Date and time math sounds trivial until you are actually doing it. How old is someone born on March 3rd, 1987 — in years, months, and days as of today? How many days fall between two dates when one month has 30 days, the next has 31, and February complicates the count? What is 9:30 AM Pacific in London, Karachi, and Tokyo simultaneously? None of these are conceptually difficult, but doing them by hand is tedious and error-prone.

The tools below cover every common date and time calculation — age, date arithmetic, time zone conversion, Unix timestamps, elapsed time, and real-time counting. All run in your browser, require no account, and store nothing. The full calculator collection is in the Calculators hub.

Age Calculator

Knowing someone's exact age — in years, months, and days — comes up more often than casual conversation: forms, eligibility checks, medical contexts, and legal requirements all specify age to a precise level that "they are around 43" does not satisfy.

The Age Calculator takes a date of birth and computes the precise age as of today: years, months, and days remaining. It also shows the total age expressed in months alone, in weeks alone, and in days alone — so you can answer "how many days old am I?" instantly. The next birthday and the number of days until it are shown as well.

Three scenarios where the exact figure matters:

• Checking whether someone meets a minimum age requirement where the threshold is 18 years exactly, not "around 18"
• Filling out government or medical forms that request age in years and months separately
• Calculating a child's developmental age for growth chart comparisons, where the pediatric standard is age in months rather than a rounded integer

The calculator also works in reverse: enter a target age and it returns the corresponding birth year. Useful when you know someone is 42 and need to confirm the birth year without doing mental subtraction under pressure.

Date Calculator

The Date Calculator handles two distinct types of calculation. The first is date difference: enter a start date and end date, and the calculator returns the exact interval expressed as years, months, and days, or as a total number of days, business days, or weeks.

The second mode is date arithmetic: start from any date and add or subtract a number of days, weeks, months, or years to land on a target date.

Date difference examples:

• A 90-day supply contract starts February 12th — when does it expire? The calculator returns May 13th, correctly accounting for February's length and any leap year status
• A loan matures 18 months from October 1st — what is the exact maturity date?
• How many business days fall between a project kickoff and a delivery deadline?

Date arithmetic examples:

• A product warranty runs 2 years from purchase date — enter the purchase date, add 2 years, get the precise expiry
• A probationary period ends 90 days from a hire date — the calculator returns the exact end date without counting on a wall calendar
• Subscription billing renews every 30 days — when does the next charge fall?

The business-day mode strips out weekends, which is the default interpretation of "days" in most contracts and legal notices.

Time Calculator

When the calculation involves hours and minutes rather than calendar dates, the Time Calculator is the right tool. It adds, subtracts, multiplies, and divides time values expressed in hours, minutes, and seconds — no decimal conversion needed.

Common use cases:

• Totalling weekly billable hours logged in hours:minutes format — 2h 45m + 3h 20m + 1h 55m produces an exact total without converting each entry to 2.75, 3.33, and 1.92 first
• Finding elapsed duration between a start and end time: an event runs from 10:15 AM to 2:40 PM — how long is that?
• Dividing shift hours across multiple employees for payroll calculations
• Summing audio or video clip durations to find the total runtime of a project

The most practical use is billable hour tracking. Independent contractors who log time in hours:minutes can total a full week of entries directly, without the rounding errors that decimal-hour conversion introduces when the minutes do not divide cleanly.

Time Zone Converter

Any coordination across regions requires a time zone check. "Let's meet at 3 PM" is ambiguous the moment participants are in different cities. "3 PM Eastern" removes the ambiguity for the sender but still requires mental arithmetic for everyone else.

The Time Zone Converter takes a time and source zone and returns the equivalent across multiple destinations simultaneously — enter 3 PM Eastern and see Pacific, London, Berlin, India, Tokyo, and Sydney in one lookup. No switching tools, no sequential conversions.

The converter handles situations where the offset is not a clean hour: India (UTC+5:30), Nepal (UTC+5:45), and the Chatham Islands (UTC+12:45) are all handled correctly. Daylight saving transitions are encoded automatically — you do not need to know whether a given region is currently on summer time.

The two directions are equally useful. The obvious direction is "I am in Pacific time, what time should I send this to reach my London contact at 9 AM?" The reverse direction — "a conference call is scheduled for 14:00 UTC, what is that for me locally?" — is just as common and just as easy to get wrong without the tool.

Unix Timestamp Converter

Unix timestamps appear in log files, API responses, database records, and URLs across virtually every web application. The number 1751011200 is a valid timestamp — but knowing that it represents June 27, 2026 at 12:00 AM UTC requires conversion that is impossible to do mentally.

The Unix Timestamp Converter converts in both directions: timestamp to human-readable date and time, and date/time to timestamp. It displays the result in UTC, your local time zone, and the raw epoch value in both seconds and milliseconds.

When you need it:

• Debugging an API response where dates appear as epoch milliseconds rather than ISO strings
• Reading server error logs that stamp events in Unix time and need to be correlated with a real timeline
• Verifying that a scheduled automation will fire at the expected calendar time
• Checking the expiry time of a JWT token — the exp claim is always a Unix timestamp
• Calculating the exact duration between two timestamped events by subtracting raw epoch values

Developers encounter this daily. Non-developers encounter it less frequently but find it equally opaque when they do — the converter is built for both audiences.

Stopwatch

Some measurements are not in calendar units at all — they are real-time events: how long a task actually takes, how fast a physical process runs, or whether a presentation hits the target duration before the audience tunes out.

The Stopwatch runs directly in your browser with start, stop, and lap controls. No install, no app, no sign-in. Practical for:

• Timing a presentation or speech rehearsal to confirm it fits a hard time slot
• Tracking actual time spent on a task for productivity monitoring or billing verification
• Timing physical activities — rest periods between sets, cooking steps, interval exercises
• Running informal speed measurements on manual processes to find where time is actually going

The browser stopwatch is accurate to the millisecond for any practical timing use, and it is available the moment you open the page.

Frequently Asked Questions

How do I calculate how many days are between two dates?
Use the Date Calculator: enter the start date and end date and select "date difference." The result shows total days, business days, and the interval broken into years, months, and remaining days.

How do I find my exact age in years, months, and days?
The Age Calculator computes the precise age as of today from any date of birth. It returns the result in years + months + days and also shows the total expressed in months and in days.

How do I convert a Unix timestamp to a readable date?
Paste the timestamp (in seconds or milliseconds) into the Unix Timestamp Converter. It returns the date and time in both UTC and your local time zone. You can also enter a date to get its timestamp.

What time is it in another country right now?
The Time Zone Converter shows the current time in any time zone and converts any entered time to multiple destinations at once, with daylight saving rules applied automatically.

How do I add 90 days to a specific date?
In the Date Calculator, select "add time to date," enter the start date, and type 90 in the days field. The calculator returns the resulting date accounting for varying month lengths and leap years.

Can I use these tools without an internet connection?
All six tools perform calculations locally in your browser with no server calls during use. Once the page has loaded, they function without an active network connection.

All six tools above are free, require no account, and store no data. Every calculation stays in your browser — close the tab and nothing is retained. The full set of free calculators is in the Calculators hub, and every Nutilz tool is listed on the homepage.