Calender holidays are referred to as those holidays which are marked, known and unannounced holidays of a specific country or a nation. Each country's calendar holidays differ from one another. These may also be called public holidays. One holiday that is mostly common throughout the world is Sunday that is an off from work. On Sundays as holiday people are given an off from their work and jobs and spend their time with families and entertain themselves as they desire. This holiday occurs every week throughout the world.

There are also other calender holidays like Labor Day, and holy events like Christmas day and Easter which are celebrated same day everywhere but with different traditions and customs.

Muslim and non Muslims' calendar holidays differ in nature owing to their religious practices. For e.g. Eid holidays are observed throughout the Muslim world but for non Muslim nations it continues to be a usual working day. Apart from the occasion of Eid the Muslim world observes holidays for their sacred nights and the 9^th and 10^th of their sacred month of Muharram. These dates occupy a holiday in the Islamic calendar. Moreover dates that are associated with the birth and death of religious figures are also frequently celebrated providing them additional calendar holidays.

Not only the religion separates holidays of each nation, Independence Day is a day which is observed by every nation throughout the world, with a single name but on different dates. This is celebrated with equal zest and patriotism by every country along with the vows, oaths and promises. This is an occasion that people of one country celebrates together regardless of race, religion, sects etc. This is celebrated by the entire country carrying a similar patriotism. This celebration reunites the people living in one country to celebrate a common event.

European countries have many common holidays like Veteran's Day and Thanksgiving Day in the month of November, Columbus Day for the Americans in October, Memorial Day on the 31^st of May and President Day on the 15^th of February.

There are also many other occasions that are celebrated worldwide lie children's day, Mothers Day, Fathers Day, Valentine's Day but they do not acquire a position of calendar holidays. Though they are enthusiastically celebrated, they do not provide the calender holidays.

When the years pass every nation, country or the world undergoes certain changes. These may be positive or negative changes. These maybe positive or negative associated with various events. When these events gain importance it is likely that in future years they are mourned over or celebrated with joy in the memory of any incident or person. Therefore these calender holidays do not necessarily remain constant in terms of dates and number.