class calendar.Calendar(firstweekday=0)  
Creates a Calendar object. firstweekday is an integer specifying the first day of the week. 0 is Monday (the default), 6 is Sunday. A Calendar object provides several methods that can be used for preparing the calendar data for formatting. This class doesn’t do any formatting itself. This is the job of subclasses. Calendar instances have the following methods:  
iterweekdays()  
Return an iterator for the week day numbers that will be used for one week. The first value from the iterator will be the same as the value of the firstweekday property. 
  
itermonthdates(year, month)  
Return an iterator for the month month (1–12) in the year year. This iterator will return all days (as datetime.date objects) for the month and all days before the start of the month or after the end of the month that are required to get a complete week. 
  
itermonthdays(year, month)  
Return an iterator for the month month in the year year similar to itermonthdates(), but not restricted by the datetime.date range. Days returned will simply be day of the month numbers. For the days outside of the specified month, the day number is 0. 
  
itermonthdays2(year, month)  
Return an iterator for the month month in the year year similar to itermonthdates(), but not restricted by the datetime.date range. Days returned will be tuples consisting of a day of the month number and a week day number. 
  
itermonthdays3(year, month)  
Return an iterator for the month month in the year year similar to itermonthdates(), but not restricted by the datetime.date range. Days returned will be tuples consisting of a year, a month and a day of the month numbers.  New in version 3.7.  
  
itermonthdays4(year, month)  
Return an iterator for the month month in the year year similar to itermonthdates(), but not restricted by the datetime.date range. Days returned will be tuples consisting of a year, a month, a day of the month, and a day of the week numbers.  New in version 3.7.  
  
monthdatescalendar(year, month)  
Return a list of the weeks in the month month of the year as full weeks. Weeks are lists of seven datetime.date objects. 
  
monthdays2calendar(year, month)  
Return a list of the weeks in the month month of the year as full weeks. Weeks are lists of seven tuples of day numbers and weekday numbers. 
  
monthdayscalendar(year, month)  
Return a list of the weeks in the month month of the year as full weeks. Weeks are lists of seven day numbers. 
  
yeardatescalendar(year, width=3)  
Return the data for the specified year ready for formatting. The return value is a list of month rows. Each month row contains up to width months (defaulting to 3). Each month contains between 4 and 6 weeks and each week contains 1–7 days. Days are datetime.date objects. 
  
yeardays2calendar(year, width=3)  
Return the data for the specified year ready for formatting (similar to yeardatescalendar()). Entries in the week lists are tuples of day numbers and weekday numbers. Day numbers outside this month are zero. 
  
yeardayscalendar(year, width=3)  
Return the data for the specified year ready for formatting (similar to yeardatescalendar()). Entries in the week lists are day numbers. Day numbers outside this month are zero.