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Beginning of solar calendar year
The sun behind the Heel Stone of Stonehenge, at sunrise on the summer solstice
The Solar New Year is the beginning of the solar calendar year. This event is observed at different times of year and with varying practices in cultures across the globe. The
most common bases chosen to begin a new calendar year are the winter solstice, summer solstice, the spring equinox and the autumnal equinox. South and South-east Asian solar calendars are more formally linked to astronomical events.
Some of the more widely known solar new year celebrations include:
Enkutatash (Ethiopian calendar): about ten days before the autumnal equinox
January 1 in the Gregorian and Julian calendars (same number, different days): at present about twelve and twenty-five days respectively after the northern winter solstice.
Iranian New Year (Nowruz) : precisely the northern spring equinox
The Julian calendar gains a day against the true solar year every 129 years. In other words, the Julian calendar gains 3.1 days every 400 years, while the Gregorian calendar gains 0.1 day over the same time. The Julian calendar will gain another day in 2100 but the Gregorian will not.
