topic creating dummy variable from dates in SAS Programming

creating dummy variable from dates

sks521 — Mon, 17 Jun 2019 12:01:15 GMT

Hi,

I am trying to create a dummy variable as follows;

before 1st September 2016 as pre-intervention;

from 01/09/2016 to 28/02/2017 as intervention

After 28/02/2017 as post-intervention

If I run proc contents, the log says its in 'yymmdd10' format;

in proc print output log the dates look like for e.g.;

2018-06-18.

When I write the following syntax;

data dummy;
set combined;
format EventDate YYMMDD10.;
if EventDate<'20160901'd then group=0;*intervention;
else if '20160901'd =<EventDate>= '20170228'd then group=1;*pre-intervention;
else group=2;*post-intervention;
run;

it gives me an error message.

Can someone help please?

Thanks

Shah

Re: creating dummy variable from dates

PaigeMiller — Mon, 17 Jun 2019 12:08:35 GMT

@sks521 wrote:

if EventDate<'20160901'd then group=0;*intervention;

The proper syntax here is:

if EventDate<'01SEP2016'd then group=0;

It doesn't matter what the format of the variable is, your date constant must be in the format shown.

Re: creating dummy variable from dates

sks521 — Mon, 17 Jun 2019 12:12:38 GMT

Fabulous! it worked

Thanks

Re: creating dummy variable from dates

Ksharp — Mon, 17 Jun 2019 12:32:03 GMT

Your date constant is not right.

'20160901'd

-->

'01sep2016'd