Archives: World Calendars

GPS Time is a technical timescale used by the Global Positioning System and differs from UTC because of leap-second treatment.

Unix time is a machine-oriented timestamp rather than a cultural calendar, but it is central to modern digital chronology.

Modified Julian Date shortens the Julian Date number and shifts the day boundary to midnight for convenient technical use.

Julian Date is not the same thing as the Julian calendar. Astronomers use it as a continuous numerical time variable; at 0h UT1, the Julian Date ends in .5.

ISO 8601 provides unambiguous numeric date/time representations and includes week dates, ordinal dates, time intervals and UTC-related formats.

The Positivist calendar tied timekeeping to a commemorative program of historical figures and illustrates how calendar design can encode ideology.

The World Calendar proposal aimed to make quarters structurally identical. Objections included the treatment of extra days outside the seven-day week cycle.

The International Fixed Calendar sought regularity and month-to-month symmetry but was never adopted as the global civil standard.

These were work-schedule reforms rather than a complete replacement of the Gregorian date system. They are important examples of modern attempts to redesign the social week.

The Rumi calendar arose from the need to align taxation and administration more closely with the solar year than the lunar Hijri calendar allowed.