Data about each month (SAS)

Do you remember this old old nursery rhyme?

30 days hath September,
April, June and November,
All the rest have 31,
Excepting February alone
(And that has 28 days clear,
With 29 in each leap year).

Ne neither, and I don’t need to because I use SAS code to generate information about each month, including the number of days in each month, using SAS’s powerful intnx and intck functions to do the hard work. It’s also a good example of using a DATA step to generate a data set without an input data set (i.e., no SET or MERGE statements).

data months;
	format first_day last_day yymmdd10.;
	do year = 2013 to 2020;
		do month = 1 to 12;
			first_day = mdy(month, 1, year);
			last_day = intnx('month', first_day, 0, 'e');
			days  = intck('day', first_day, last_day) + 1;
			weekdays  = intck('weekday', first_day, last_day) + 1;
			weeks  = intck('week', first_day, last_day);
			hours  = intck('dthour', dhms(first_day, 0, 0,0), dhms(last_day, 23, 59, 59)) + 1;
			work_hours = weekdays * 8;
			output;
		end; /* end month */
	end; /* end year */
	label
		first_day = 'First day'
		last_day = 'Last day'
		days = 'Days'
		weekdays = 'Week days'
		weeks = 'Weeks'
		hours = 'Hours'
		work_hours = 'Work hours'
		;
	drop month year;
run;

Here are the results:

First day	Last day	Days	Week days	Weeks	Hours	Work hours
1/1/2013	1/31/2013	31	23	4	744	184
2/1/2013	2/28/2013	28	20	4	672	160
3/1/2013	3/31/2013	31	21	5	744	168
4/1/2013	4/30/2013	30	22	4	720	176
5/1/2013	5/31/2013	31	23	4	744	184
6/1/2013	6/30/2013	30	21	5	720	168
7/1/2013	7/31/2013	31	23	4	744	184
8/1/2013	8/31/2013	31	22	4	744	176
9/1/2013	9/30/2013	30	22	4	720	176
10/1/2013	10/31/2013	31	23	4	744	184
11/1/2013	11/30/2013	30	21	4	720	168
12/1/2013	12/31/2013	31	23	4	744	184
1/1/2014	1/31/2014	31	23	4	744	184
2/1/2014	2/28/2014	28	21	4	672	168
3/1/2014	3/31/2014	31	22	5	744	176
4/1/2014	4/30/2014	30	22	4	720	176
5/1/2014	5/31/2014	31	22	4	744	176
6/1/2014	6/30/2014	30	22	4	720	176
7/1/2014	7/31/2014	31	23	4	744	184
8/1/2014	8/31/2014	31	21	5	744	168
9/1/2014	9/30/2014	30	22	4	720	176
10/1/2014	10/31/2014	31	23	4	744	184
11/1/2014	11/30/2014	30	21	5	720	168
12/1/2014	12/31/2014	31	23	4	744	184
1/1/2015	1/31/2015	31	22	4	744	176
2/1/2015	2/28/2015	28	21	3	672	168
3/1/2015	3/31/2015	31	23	4	744	184
4/1/2015	4/30/2015	30	22	4	720	176
5/1/2015	5/31/2015	31	21	5	744	168
6/1/2015	6/30/2015	30	22	4	720	176
7/1/2015	7/31/2015	31	23	4	744	184
8/1/2015	8/31/2015	31	22	5	744	176
9/1/2015	9/30/2015	30	22	4	720	176
10/1/2015	10/31/2015	31	22	4	744	176
11/1/2015	11/30/2015	30	22	4	720	176
12/1/2015	12/31/2015	31	23	4	744	184
1/1/2016	1/31/2016	31	21	5	744	168
2/1/2016	2/29/2016	29	21	4	696	168
3/1/2016	3/31/2016	31	23	4	744	184
4/1/2016	4/30/2016	30	21	4	720	168
5/1/2016	5/31/2016	31	23	4	744	184
6/1/2016	6/30/2016	30	22	4	720	176
7/1/2016	7/31/2016	31	21	5	744	168
8/1/2016	8/31/2016	31	23	4	744	184
9/1/2016	9/30/2016	30	22	4	720	176
10/1/2016	10/31/2016	31	22	5	744	176
11/1/2016	11/30/2016	30	22	4	720	176
12/1/2016	12/31/2016	31	22	4	744	176
1/1/2017	1/31/2017	31	23	4	744	184
2/1/2017	2/28/2017	28	20	4	672	160
3/1/2017	3/31/2017	31	23	4	744	184
4/1/2017	4/30/2017	30	21	5	720	168
5/1/2017	5/31/2017	31	23	4	744	184
6/1/2017	6/30/2017	30	22	4	720	176
7/1/2017	7/31/2017	31	22	5	744	176
8/1/2017	8/31/2017	31	23	4	744	184
9/1/2017	9/30/2017	30	21	4	720	168
10/1/2017	10/31/2017	31	23	4	744	184
11/1/2017	11/30/2017	30	22	4	720	176
12/1/2017	12/31/2017	31	21	5	744	168
1/1/2018	1/31/2018	31	23	4	744	184
2/1/2018	2/28/2018	28	20	4	672	160
3/1/2018	3/31/2018	31	22	4	744	176
4/1/2018	4/30/2018	30	22	4	720	176
5/1/2018	5/31/2018	31	23	4	744	184
6/1/2018	6/30/2018	30	21	4	720	168
7/1/2018	7/31/2018	31	23	4	744	184
8/1/2018	8/31/2018	31	23	4	744	184
9/1/2018	9/30/2018	30	21	5	720	168
10/1/2018	10/31/2018	31	23	4	744	184
11/1/2018	11/30/2018	30	22	4	720	176
12/1/2018	12/31/2018	31	22	5	744	176
1/1/2019	1/31/2019	31	23	4	744	184
2/1/2019	2/28/2019	28	20	4	672	160
3/1/2019	3/31/2019	31	21	5	744	168
4/1/2019	4/30/2019	30	22	4	720	176
5/1/2019	5/31/2019	31	23	4	744	184
6/1/2019	6/30/2019	30	21	5	720	168
7/1/2019	7/31/2019	31	23	4	744	184
8/1/2019	8/31/2019	31	22	4	744	176
9/1/2019	9/30/2019	30	22	4	720	176
10/1/2019	10/31/2019	31	23	4	744	184
11/1/2019	11/30/2019	30	21	4	720	168
12/1/2019	12/31/2019	31	23	4	744	184
1/1/2020	1/31/2020	31	23	4	744	184
2/1/2020	2/29/2020	29	21	4	696	168
3/1/2020	3/31/2020	31	23	4	744	184
4/1/2020	4/30/2020	30	22	4	720	176
5/1/2020	5/31/2020	31	21	5	744	168
6/1/2020	6/30/2020	30	22	4	720	176
7/1/2020	7/31/2020	31	23	4	744	184
8/1/2020	8/31/2020	31	22	5	744	176
9/1/2020	9/30/2020	30	22	4	720	176
10/1/2020	10/31/2020	31	22	4	744	176
11/1/2020	11/30/2020	30	22	4	720	176
12/1/2020	12/31/2020	31	23	4	744	184

Tested with SAS 9.3 on Windows 7.