Our Days Are Numbered: 7 Crazy Facts About Calendars: Quick Facts

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Circular carved stone disc with a central face surrounded by concentric rings of intricate symbols and geometric patterns in relief.

Detail from Luca Signorelli's fresco The Deeds of the Antichrist, showing the Antichrist in a red robe being whispered to by a horned, bare-chested Satan, with onlookers in the background.

Diagram showing Earth's orbit around the Sun with labeled positions for the summer solstice, winter solstice, vernal equinox, and autumnal equinox, illustrating how Earth's tilt causes the seasons.

Montana: Flathead Lake

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calendar Gregorian calendar Advent calendar week French republican calendar Julian calendar month solar calendar International Date Line lunar calendar day