Calculating Dates

此案例用calendar模块计算每月特定事件对应的日期。例如，某单位小组会议在每月的第二个星期四召开，计算一年内这个日子，使用monthcalendar()

Although the calendar module focuses mostly on printing full calendars in various formats, it also provides functions useful for working with dates in other ways, such as calculating dates for a recurring event. For example, the Python Atlanta Users’ Group meets on the second Thursday of every month. To calculate the dates for the meetings for a year, use the return value of monthcalendar(）.

To calculate the group meeting dates for a year, assuming they are always on the second Thursday of every month, look at the output of monthcalendar()

The following is the example program’s code:

import calendar

import sys

year = int(sys.argv[1])  # 运行程序时输入的年份参数，转成整型， 在控制台下输入： python 程序名.py year（例如2023）

# show every month,
for month in range(1, 13):
    
    # Compute the dates for each week that overlaps the month,
    c = calendar.monthcalendar((year, month))
    first_week = c[0]
    second_week = c[1]
    third_week = c[2]
    
    # If there is a Thursday in the first week,
    # the second Thursday is in the second week.
    # Otherwise, the second Thursday must be in 
    # the third week.
    if first_week[calendar.THURSDAY]:
        meeting_date = second_week[calendar.THURSDAY]
    else:
        meeting_date = third_week[calendar.THURSDAY]
    print('{:>3} {:>2}'.format(calendar.month_abbr[month], meeting_date))

Thus, the meeting schedule for the year is as follows:

D:\My_Project>python date_time_demo.py 2023
Jan 12
Feb  9
Mar  9
Apr 13
May 11
Jun  8
Jul 13
Aug 10
Sep 14
Oct 12        
Nov  9        
Dec 14        
              
D:\My_Project>