base calendar

It was adopted for civic matters and is a solar based calendar, assigning a date to each solar day.

The date for the festival is set according the Tibetan calendar, which is a Lunar based calendar.

The Tabular Islamic calendar also deviates from the observation based calendar in the short term for various reasons.

It will sync with Microsoft Outlook, but not with Web or Mac based calendars.

Since the calendar uses astronomical calculation for determining the vernal equinox, it has no intrinsic error, but this makes it an observation based calendar.

However, since the Hebrew calendar was based on witnesses' testimony, that had become far too dangerous to collect, Hillel II recommended change to a mathematically based calendar that was adopted at a clandestine, and maybe final, meeting in 358.

It is unusual in comparison with Argentine schools because BAICA's school year starts in August, in keeping with a more US or international based calendar, whereas the Argentine school year begins in February.

The Karaite calendar is identical to the Rabbinical calendar used before the Sanhedrin changed the Rabbinic calendar from the lunar, observation based calendar, to the current mathematically based calendar used in Rabbinic Judaism today.