Who runs this site
I'm a web developer, UI/UX designer and AI engineer. I wrote the code behind every calculator here, I write the guides, and I check each result against test cases before a page goes live. You can find me on LinkedIn.
What the calculators are for
Timespanly answers everyday time and date questions: how long it is between two times, what date falls a set number of days from today, how many hours you worked in a shift. Each calculator gives the answer first and then shows how it got there, with worked examples and the cases that trip people up, like spans past midnight, the end of a month and daylight saving changes.
New calculators are added only after they pass their tests.
Calculators and guides
- Time Duration Calculator: hours and minutes between two times or dates
- Days From Today: the date a number of days before or after today
- Add & Subtract Time: totals of hours, minutes and seconds
- Hours Calculator: hours worked in a shift or a week, with breaks
- Days Between Dates: days, weeks, months and weekdays between dates
The guides answer the questions behind the calculators, such as how many days are left in the year. New guides are added every week.
How I keep the results right
All calculators share one piece of date and time code. It runs more than 100 automated tests before every release, including a check of every day from 1900 to 2100 against a second calendar. The rules it follows, such as what happens when you add one month to January 31, are written out on the methodology page.
How pages are written
Each page starts from the questions people actually ask about a date or time problem. Every number on a page, including the examples and tables, is worked out by the same code the calculators use, so the text and the results cannot disagree. Rules that come from outside the site, such as daylight saving dates or the 40-hour overtime line, are checked against official sources before they are written down.
Pages show the date they were published and the date they last changed in a way you would notice. When a mistake is found, the page is fixed and its updated date changes with it.
The site is independent. No company pays to be mentioned, and there are no paid links or sponsored posts.
What happens to what you type
The math runs in your browser. Nothing you type into a calculator is sent to a server or stored, and there are no accounts. The privacy policy has the details.
Ads
There are no ads on the site right now. If ads are added later, they will sit below the results and never inside a calculator.
Found a mistake?
Tell me on the contact page. A wrong result gets fixed before anything else.