count days in the first week

[alo_moon]

I'm new to sas and would like learn to calculate:

How many days in the first week of the year?

For example:

Year = 2016, Week = 1

num_days: 2 days

Year = 2020, week = 1

num_days: 4 days

[FreelanceReinh · Accepted solution]

Hello @alo_moon and welcome to the SAS Support Communities!

You can use the WEEKDAY function (together with the MDY function and a simple calculation) to get the desired result:

data want;
input year;
num_days=8-weekday(mdy(1,1,year));
cards;
2016
2020
;

[Ksharp]

data want;
input year;
date=mdy(1,1,year);
num_days=intnx('week',date,1)-date;
cards;
2016
2020
;