FAQ

DatePrism is a free application for Windows and Android that calculates and converts dates between the Gregorian calendar and the main Masonic calendars (French Rite, Scottish Rite, Royal Arch, Knights Templar). It can also calculate anniversary dates (the 1,000th day of an event, for example) and the exact gap between two dates.

No. The tool for calculating dates to celebrate (1,000th day, personal or professional anniversaries) is meant for everyone. Conversion to the Masonic calendars is a specific feature designed for the Masonic community, but it does not prevent a purely civil use of the application.

The calculations are based on the JDN (Julian Day Number) system, which measures time continuously from a fixed astronomical origin, ensuring precision independent of each calendar's specific features.

The historical convention has no year 0: year 1 BC is immediately followed by year 1 AD. As soon as an entered or calculated date corresponds to a year less than or equal to 0 in one of the displayed calendars, DatePrism automatically adds the equivalent in ISO 8601 format (which does include a year 0) to avoid any ambiguity.

The French Rite (Anno Lucis, starting March 1st), the Scottish Rite (Anno Mundi, starting September 1st), the Royal Arch (Anno Inventionis) and the Knights Templar (Anno Ordinis).

Enter the event's date in the "Date 1" field, enter 1000 in the "Celebrate" field with the "Days" unit, then click "Calculate". The exact date of that 1,000th day will be displayed, converted into all selected calendars.

Enter Date 1 and Date 2: DatePrism will then automatically hide the offset and filter fields to display instead the exact gap between the two dates, in days, weeks, months, and in full years/months/weeks/days form.

On Windows, the "Copy" button directly copies the entire results window to the clipboard. On Android, tap "Select", select the desired text via the standard Android menu, then tap "Lock" to return to normal mode.

No, DatePrism is entirely free, with no ads and no trackers. If you find the application useful, you can support its development via a PayPal donation (see the Donate page).

French, English, Spanish, German and Italian. The application automatically detects your system language, which you can change at any time in the Options menu.

The results are indicative, calculated according to precise and documented conversion rules, but they do not replace a specialized historical reference when one exists, particularly for very old dates or special cases linked to certain obediences.

Yes, all calculations are performed locally on your device, with no internet connection required and no data collection.