A holiday is a day set aside by custom or by law on which normal activities, especially business or work, are suspended or reduced. Generally, holidays are intended to allow individuals to celebrate or commemorate an event or tradition of cultural or religious significance. Holidays may be designated by governments, religious institutions, or other groups or organizations. The degree to which normal activities are reduced by a holiday may depend on local laws, customs, the type of job being held or even personal choices.
The concept of holidays has most often originated in connection with religious observances. The intention of a holiday was typically to allow individuals to tend to religious duties associated with important dates on the calendar. In most modern societies, however, holidays serve as much of a recreational function as any other weekend days or activities.
Source : http://en.m.wikipedia.org/wiki/Holiday