A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A date is the designation...

The Gregorian calendar is the calendar used in most parts of the world. It went into effect in October 1582 following the papal bull Inter gravissimas...

Hijri calendar (Arabic: ٱلتَّقْوِيم ٱلْهِجْرِيّ, romanized: al-taqwīm al-hijrī), or Arabic calendar also known in English as the Muslim calendar and Islamic...

Julian calendar is a solar calendar of 365 days in every year with an additional leap day every fourth year (without exception). The Julian calendar is still...

The traditional Chinese calendar (traditional Chinese: 農曆; simplified Chinese: 农历; lit. 'agricultural calendar'; informally traditional Chinese: 陰曆; simplified...

Indian national calendar, called the Shaka calendar or Śaka calendar, is a solar calendar that is used alongside the Gregorian calendar by The Gazette...

The Hebrew calendar (Hebrew: הַלּוּחַ הָעִבְרִי, romanized: HalLûaḥ HāʿIḇrî), also called the Jewish calendar, is a lunisolar calendar used today for...

The Hindu calendar, also called Panchanga (Sanskrit: पञ्चाङ्ग), is one of various lunisolar calendars that are traditionally used in the Indian subcontinent...

The Ethiopian calendar (Amharic: ዓውደ ወር; Ge'ez: ዓዉደ ወርሕ; Tigrinya: ዓዉደ ኣዋርሕ), or Ge'ez calendar (Ge'ez: ዓዉደ ወርሕ; Tigrinya: ዓዉደ ኣዋርሕ; Amharic: የኢትዮጲያ ዘመን...

A lunar calendar is a calendar based on the monthly cycles of the Moon's phases (synodic months, lunations), in contrast to solar calendars, whose annual...