These graphics explain why Easter Sunday changes each year based on ancient interpretations of the solar and lunar cycles.

The next full moon is at 12:56 pm EST on Monday, May 12 and is known as the Flower Moon. Here is a look at all the full moons ...

Carvings on a 12,000-year-old monument in Turkey appear to mark solar days and years, making it possibly the oldest solar ...

Year-round schools have long been thought to potentially improve academics by reducing the length of summer break. Research ...

If it seems as if Easter is late this year, you're right. But it's not as late as it could be. Easter's date is based on the lunar calendar. Easter comes on the first Sunday after the first full ...