When people change their calendar from one year to the next they like to celebrate In fact people have been celebrating the beginning of a new year for thousands of years But a new year does not have to begin in the middle of winter on the first day of a month called January That’s because people living at different times in different parts of the world have had different calendars And they still do 3
HOW WE MEASURE TIME When people first began to make calendars they used some ideas based on science A day is the time it takes Earth to make one complete rotation about 24 hours A month is based on the time it takes the Moon to travel around Earth The word month comes from moon Each moon cycle is about 29 and 1 2 days A year is the time it takes Earth to travel around the sun Each year is about 365 days The summer solstice is the longest day of the year The winter solstice is the shortest On the spring and autumn equinoxes night and day are equal in length EARTH S SEASONS EQUINOX March 20 Spring begins SOLSTICE June 21 Summer begins Spring Winter Summer Autumn SOLSTICE December 21 Winter begins EQUINOX September 22 Autumn begins
ANCIENT CALENDARS Ancient peoples often began their new year on the first day of spring around March 20 But other people began their new year on the first day of fall on the first day of winter or at other times of the year 5
