# gregorian::gregorian_calendar

Overall Index -- Gregorian Index -- Posix Time Index

Date Documentation

Header -- Functions

## Introduction

The class boost::gregorian::gregorian_calendar implements the functions necessary to create the gregorian date system. It converts to the year-month-day form of a date to a day number representation and back.

For most purposes this class is simply accessed by gregorian::date and is not used directly by the user. However, there are useful functions that might be of use such as the end_of_month_day function.

The print month example demonstrates this.

## Header

    #include "boost/date_time/gregorian/gregorian.hpp" //include all types plus i/o
    or
    #include "boost/date_time/gregorian/gregorian_types.hpp" //no i/o just types

## Functions

Syntax | Description | Example
static short day_of_week(ymd_type) | Return the day of the week (0==Sunday, 1==Monday, etc) | See also gregorian::date day_of_week
static date_int_type day_number(ymd_type) | Convert a ymd_type into a day number. The day number is an absolute number of days since the epoch start. |
static short end_of_month_day(year_type, month_type) | Given a year and month determine the last day of the month. |
static ymd_type from_day_number(date_int_type) | Convert a day number to a ymd struct. |
static bool is_leap_year(year_type) | Returns true if specified year is a leap year. | gregorian_calendar::is_leap_year(2000) --> true