python date for alug

every21days.py

import datetime
date=datetime.date(2014,7,17)
print('{d}'.format(d=date))
for _ in range(12):
    date=date+datetime.timedelta(days=21)
    print('{d}'.format(d=date))

notes.txt

This was for http://lists.alug.org.uk/pipermail/main/2014-July/033313.html

output

mak@crab 571 ~ $ python every21days.py 
2014-07-17
2014-08-07
2014-08-28
2014-09-18
2014-10-09
2014-10-30
2014-11-20
2014-12-11
2015-01-01
2015-01-22
2015-02-12
2015-03-05
2015-03-26

mak@crab 575 ~ $ python second-tue.py 
first day of month is Wednesday 01 January 2014
Tuesday #1 is Tuesday 07 January 2014
Tuesday #2 is Tuesday 14 January 2014
Second Tuesday: Tuesday 14 January 2014
first day of month is Saturday 01 February 2014
Tuesday #1 is Tuesday 04 February 2014
Tuesday #2 is Tuesday 11 February 2014
Second Tuesday: Tuesday 11 February 2014
first day of month is Saturday 01 March 2014
Tuesday #1 is Tuesday 04 March 2014
Tuesday #2 is Tuesday 11 March 2014
Second Tuesday: Tuesday 11 March 2014
first day of month is Tuesday 01 April 2014
Tuesday #1 is Tuesday 01 April 2014
Tuesday #2 is Tuesday 08 April 2014
Second Tuesday: Tuesday 08 April 2014
first day of month is Thursday 01 May 2014
Tuesday #1 is Tuesday 06 May 2014
Tuesday #2 is Tuesday 13 May 2014
Second Tuesday: Tuesday 13 May 2014
first day of month is Sunday 01 June 2014
Tuesday #1 is Tuesday 03 June 2014
Tuesday #2 is Tuesday 10 June 2014
Second Tuesday: Tuesday 10 June 2014
first day of month is Tuesday 01 July 2014
Tuesday #1 is Tuesday 01 July 2014
Tuesday #2 is Tuesday 08 July 2014
Second Tuesday: Tuesday 08 July 2014
first day of month is Friday 01 August 2014
Tuesday #1 is Tuesday 05 August 2014
Tuesday #2 is Tuesday 12 August 2014
Second Tuesday: Tuesday 12 August 2014
first day of month is Monday 01 September 2014
Tuesday #1 is Tuesday 02 September 2014
Tuesday #2 is Tuesday 09 September 2014
Second Tuesday: Tuesday 09 September 2014
first day of month is Wednesday 01 October 2014
Tuesday #1 is Tuesday 07 October 2014
Tuesday #2 is Tuesday 14 October 2014
Second Tuesday: Tuesday 14 October 2014
first day of month is Saturday 01 November 2014
Tuesday #1 is Tuesday 04 November 2014
Tuesday #2 is Tuesday 11 November 2014
Second Tuesday: Tuesday 11 November 2014
first day of month is Monday 01 December 2014
Tuesday #1 is Tuesday 02 December 2014
Tuesday #2 is Tuesday 09 December 2014
Second Tuesday: Tuesday 09 December 2014

second-tue.py

import datetime
year=2014
for m in range(1,13):
    date = datetime.date(year,m,1)
    print date.strftime("first day of month is %A %d %B %Y")
    count=0
    # for quick-and-dirty simplicity, we'll loop over days and report given days of the week.
    # If you want more efficiency, use the isoweekday and use math to determine the next looked-for day, then add a week 
    while True:
      # Mon=1, Tue=2 etc
      if date.isoweekday() == 2:
        count = count + 1
        print "Tuesday #{} is {}".format(count, date.strftime("%A %d %B %Y"))
        if count == 2:
           print date.strftime("Second Tuesday: %A %d %B %Y")
           break
      date=date + datetime.timedelta(days=1)