Time variable into categorical

[Rodrigue]

Hi ! Please I need you help+++

I have a time variable HH:MM called "timestop" and I would like to create a new categorical variable "timestopnight" stating 1 if the timestop was between 23:00 and 7:00 and 0 if the timestop was between 07:00 and 23:00.

I have tried several codes like the following but none worked.

data dataset ; set dataset;

if timestop < '07:00't then timestopnight=1;

if timestop > '23:00't then timestopnight=1;

if  '07:00't =<timestop =< '23:00't then timestopnight=0;

run;

Thanks a lot for your help 🙏

Rodrigue

[tarheel13]

I think you need to use if else if.

[tarheel13]

Can also do a boolean. 

timestopnight=07:00't le timestop le 23:00't;

This will assign 1 if the condition is true and 0 if it's false.

[Kurt_Bremser · Accepted solution]

Please post the complete log from that step.

If timestop is a SAS time, this will work:

timestopnight = ifn('07:00't le timestop le '23:00't,0,1);

Be observant if timestop is a datetime instead of just time.

[Rodrigue]

Thank you very much Kurt. It seems to work perfectly well for subjects who have a time in the timestop variable.

The only problem is that I have a 1 in the timestopnight column in patients who don't have value for the timestop variable.

I've tried to insert  before but it didn't work.

timestopnight = .;

Could you help me with that ?

I have attached the log but the variable names are different since I've tried to simplify for the post.

Thanks again for your help+++

Rodrigue

[Rodrigue]

I found the solution adding 

if not missing (timestop) 

[ballardw]

MISSING values are always less than any actual value.

Always.