Easter and the holidays that are related to it are moveable feasts, in that they do not fall on a fixed date in the Gregorian or Julian calendars (both of which follow the cycle of the sun and the seasons)
As Easter always falls on a Sunday, many countries in the world also recognize Easter Monday as a public holiday.
Winter is the coldest season of the year in polar and temperate zones (winter does not occur in most of the tropical zone). It occurs after autumn and before spring in each year. Winter is caused by the axis of the Earth in that hemisphere being oriented away from the Sun.
Earth Day is an annual event scheduled for April 22 to show support for environmental protection.
