What Chronira is
Chronira answers everyday questions about dates and time: how old someone is, how many days separate two dates, which date falls 90 days or 30 business days from now, how many hours were worked this week, which ISO week it is, or what today’s date is on the Hijri calendar. Each tool gives a clear answer first, then the detail behind it.
The tools cover:
- Dates: age, days between dates, adding and subtracting days, weeks, months and years, and business days with public holidays.
- Time: adding hours and minutes, the time between two clock times, work hours and a weekly time card.
- Calendars: ISO week numbers, year calendars with week numbers, and countdowns to fixed occasions.
- The Hijri calendar: today’s Hijri date, a Hijri–Gregorian converter and expected dates of Islamic occasions on the Umm al-Qura calendar.
- Timers: online timers for classrooms, work sessions and cooking.
Why it exists
Many date and time websites are slow, cluttered, or unclear about how they reach a result. Small differences in convention matter: whether the start date is counted, what happens to 31 January plus one month, or how a 29 February birthday is treated in a common year. Chronira exists to give fast answers and to state those conventions openly, so you can trust a result or know exactly why it differs from another source.
Principles
- Calculations in your browser. Dates of birth, schedules and countdowns are processed on your device and are not sent to a server. The privacy policy lists what may be saved in your browser and how to clear it.
- No account. Nothing to sign up for, nothing to log in to.
- Honest labels. A result marked “Exact” is pure calendar arithmetic. Dates that depend on official announcements, such as the start of Ramadan or Eid, are marked “Expected”, because the official date can differ by a day from country to country.
- Documented rules. The methodology explains how every tool calculates, including edge cases and limitations, and the sources page lists the calendars, standards and laws the tools rely on.
- Corrections. Every tool has a Report an error button. Reported problems are checked, fixed when confirmed, and changes to calculation rules or data are recorded in the changelog.
Languages
Chronira is available in English, Arabic and French. The Arabic and French versions are written for their readers rather than translated word for word, and the Arabic version is laid out right to left. Spanish and Portuguese versions are planned.
Who is behind Chronira
Chronira is an independent project, built and maintained by an independent developer. It is not affiliated with any government, religious authority or calendar body. Details about the editor will be added to this page later. To ask a question or suggest an improvement, use the contact page.
Works offline
Once a page has loaded, Chronira can be installed on a phone or computer like an app and keeps working without a connection, because the calculations never needed a server in the first place.