Value | Symbolic name | Description | 
|   0 | GTK_CALENDAR_SHOW_HEADING | 
   Specifies that the month and year should be displayed.
   | 
|   1 | GTK_CALENDAR_SHOW_DAY_NAMES | 
   Specifies that three letter day descriptions should be present.
   | 
|   2 | GTK_CALENDAR_NO_MONTH_CHANGE | 
   Prevents the user from switching months with the calendar.
   | 
|   3 | GTK_CALENDAR_SHOW_WEEK_NUMBERS | 
   Displays each week numbers of the current year, down the left side of the 
calendar
   | 
|   4 | GTK_CALENDAR_WEEK_START_MONDAY | 
   Starts the calendar week on Monday, instead of the default Sunday
   |