About Time Calculator
Free time and date tools that run in your browser, with every formula stated openly and the working shown.
- 12 calculators, all free
- Runs in your browser only
- Formulas published in full
- No accounts, no sign-up
Quick answer
Time Calculator is a free set of twelve time and date tools that run entirely inside your own browser. Nothing you type is sent to a server, nothing is stored, and no account is needed. Every tool states its formula and shows the arithmetic step by step, so you can check the answer rather than trust it.
Site timecalculator.ca Tools 12, all free, no sign-up Runs on your device, in JavaScript Sent out nothing you enterWhat this site is
This is a small, deliberately narrow website. It does one family of jobs: arithmetic on hours, minutes, seconds and dates. It exists because clock time is base 60, so a pocket calculator is wrong unless you convert first, and the conversion is where people slip. Adding 2 h 45 min to 2 h 45 min gives 5 h 30 min, not 5.90. Turning 7 h 45 min into a payroll figure gives 7.75, not 7.45.
Every page pairs a working tool with an explanation of the method behind it. If you can follow the explanation, you can redo the calculation on paper and confirm what the tool told you, which is the only sensible way to use a calculator you did not write.
Who this site is for
Anyone turning a clock reading into a number that has to be right first time.
People filling in timesheets
Shift workers and small business owners who need hours worked, breaks deducted and a payroll figure.
Freelancers and invoicers
Anyone turning logged time into billable hours, or checking a week against a quote.
Students and teachers
Elapsed time homework and base 60 problems where the point is the method, not the answer.
Planners and organisers
Counting down to a date, or shifting one forward by a fixed interval.
People who care about privacy
Anyone who would rather not type a pay rate or a birth date into a form.
Our editorial standard
Three rules, applied to every page.
Every formula is stated openly. If a tool divides by 60 or adds 86,400 seconds to handle a midnight crossing, the page says so and shows the arithmetic.
decimal hours = total minutes ÷ 60 465 ÷ 60 = 7.75 overnight span = (end + 86,400 s) − start (06:00 + 86,400) − 22:00 = 8 h
The working is visible. Each calculator has a panel listing what it did, in order, with intermediate values. If a result surprises you, open it and find out where the number came from.
Figures are checked before publication. Conversion factors, table values and worked examples are recalculated rather than copied from another site. We do not invent statistics or quote studies we have not read. Where a number depends on jurisdiction, the page names the rule instead of presenting it as universal.
Every calculator on the site
Twelve tools, all free, all showing their working.
| Tool | What it does | Typical use |
|---|---|---|
| Time Calculator | Adds and subtracts hours, minutes and seconds, and converts units. | Totalling durations with mixed plus and minus. |
| Hours Calculator | Hours worked between a clock in and clock out, minus unpaid breaks. | A timesheet for one shift. |
| Time Duration Calculator | Elapsed time between two moments, with optional dates. | A gap that may cross midnight. |
| Time Card Calculator | A week of punches totalled day by day, with breaks and overtime. | Weekly or biweekly payroll preparation. |
| Decimal Hours Converter | Converts HH:MM to decimal hours and back. | Turning 7:45 into 7.75 for payroll. |
| Military Time Converter | Converts between the 12 and 24 hour clocks. | Reading a roster written as 1830. |
| Date Calculator | Days between two dates, and date plus or minus days. | Notice periods, deadlines, delivery windows. |
| Age Calculator | Exact age in years, months and days. | An age on a specific date. |
| Countdown Timer | Counts down live to a chosen date and time. | Launches, exams, events, holidays. |
| Minutes to Hours | Converts minutes into hours and minutes. | Turning 500 minutes into 8 h 20 min. |
| Seconds to Minutes | Converts seconds into minutes and seconds. | Video runtimes, lap times, timeouts. |
| Time Zone Converter | A time in one zone as local time in another. | Booking a call across countries. |
None of them require an account. If a calculation you need is missing, tell us and we will look at building it.
Why the tools show their working
A result you cannot check is one you cannot defend.
Most people using a time calculator are about to give the number to someone else. If it is questioned, "the website said so" is not an answer, so each tool exposes its intermediate steps. That also makes the site useful for learning: the Decimal Hours Converter is one division, but seeing it written out is what stops the 7:45 to 7.45 mistake happening twice.
Why everything runs on your device
Your browser does the maths and the answer never leaves the screen.
There is no server side calculation anywhere on this site. A clock in time, a birth date or an hourly rate stays in the memory of the page you are looking at. It is not posted anywhere, not written to a database, and not retained once you close the tab. Nothing is collected, so there is nothing to opt out of. The privacy policy sets out what a visit does and does not involve.
One thing is remembered. If you switch to dark mode, that preference is saved in your browser under a single key called tc-theme, so the page does not flash white next time. It holds the word light or dark and nothing else. Clearing your site data removes it.
How pages are maintained and dated
Both dates on every page mean something.
The byline shows when a page first went live and when it was last revised. We change the updated date when the content changes: a corrected figure, a rewritten explanation, a new table, a fix to the calculator. We do not touch it to make an old page look fresh.
Pages are reviewed when something prompts it: a reader reports an error, a rule we describe changes, or we spot an inconsistency while writing another page. Corrections are made to the page itself, unless the error was significant enough that a reader who relied on it deserves to see it flagged.
What these tools do not do
Clarity about the edges is part of accuracy in the middle.
This is not professional advice. Nothing here is legal, payroll, tax, medical or financial advice. A calculator can tell you a shift was 7 h 45 min. It cannot tell you whether that break should have been paid, whether overtime applies where you live, or whether a medication interval is safe.
Rules vary by jurisdiction and employer. Overtime thresholds, rounding practices and break entitlements differ by country, by region and often by contract. Where a page mentions a rule it names the source, and it is an illustration of the arithmetic rather than a statement of your rights.
Time zone data comes from your browser. The Time Zone Converter and the date tools use the time zone database shipped with your device. The browser vendor keeps it current, not us, so confirm anything critical against an official clock. Where a span crosses a daylight saving transition, elapsed hours and the difference in clock readings differ, because the day ran 23 or 25 hours.
Corrections
If a number here is wrong, we want to know before the next reader does.
Send the page address, the exact values you entered, the result the tool gave and the result you expected. Reports about a formula we stated incorrectly matter most, because a wrong explanation quietly teaches the wrong method. The contact page lists what to include.
Getting in touch
One address, read by a person.
Email hello@timecalculator.ca with corrections, bug reports, requests for a calculator that does not exist yet, or press enquiries. There is no contact form, because a form needs a server and this site has none. Please do not send payroll records or personal data: a description of the inputs is enough.
Frequently asked questions
Direct answers to the questions people ask most about this calculation.
Who is behind Time Calculator?
Time Calculator is built and maintained by a small team that writes and checks the tools and the explanations on the site. Every page is published under the site name rather than an individual byline, and the same team is responsible for the arithmetic, the tables and the corrections. Email hello@timecalculator.ca and a person reads it.
Is Time Calculator free to use?
Yes. Every one of the twelve calculators is free, with no account, no login, no trial and no paid tier. There is nothing to sign up for and no feature held back. You can use the tools as often as you like, and the pages keep working offline once they have loaded in your browser.
Do you store the times and dates I enter?
No. Every calculation runs in JavaScript inside your own browser, so the values you type never travel to a server and are never written to a database. Close the tab and they are gone. The only thing kept on your device is a single preference key called tc-theme, which records whether you chose light or dark mode.
How accurate are the calculators?
The arithmetic is exact to the second, because every tool converts inputs to a single unit, calculates, then converts back. Leap years and month lengths are handled by comparing real dates rather than estimating. The limits are stated openly: daylight saving and time zone rules come from your browser, and results should be verified independently before they are used for payroll or legal decisions.
Do you give payroll, legal or medical advice?
No. The calculators perform arithmetic and the articles explain how that arithmetic works. They do not constitute legal, payroll, tax, medical or financial advice, and they cannot account for your contract, your jurisdiction or your circumstances. For decisions that carry consequences, check the result and take advice from a qualified professional.
How do I report a mistake on the site?
Email hello@timecalculator.ca with the page address, the exact inputs you used, the result you got and the result you expected. That is normally enough to reproduce the issue quickly. Corrections are made to the page itself, and the last updated date at the top of the page changes when they are.
Can I suggest a calculator that does not exist yet?
Yes, and these suggestions are welcome. Tell us the calculation you are trying to do and what you would type in and expect out. Requests that describe a real recurring task are the ones most likely to get built, because they tend to describe a page shape that is useful to many other people as well.