Hi,
I want to calculate the number of hours from midnight, with anything between 12 p.m. and 11:59 p.m. being negative. That is, 9 P.M. is “-3,”,while 6 A.M. is “6.” I tried the using something like the following, but I do not get the desired result. The variable I have is a time variable (12 hour clock), with another variable that indicates whether the time is in a.m. or p.m.
(fallaslp_mom_v2 - 60*60*12)/3600
Any suggestions would be great. Thank you!
if ampm = "PM" then hours = time - 12; else hours = time;
If you store your am/pm variable as a boolean value, it's a simple calculation:
data have;
input hour am_pm;
cards;
6 0
9 1
;
run;
data want;
set have;
your_hour = hour - 12 * am_pm;
run;
If it's character, justa a very small change is needed:
data want;
set have;
your_hour = hour - 12 * (am_pm = 'p.m.');
run;
You are not telling us everything it seems.
This works:
data WANT;
FALLASLP_MOM_V2= '09:00:00't;
AMPM = 'PM';
HOUR = (FALLASLP_MOM_V2 - 60*60*12*(AMPM='PM'))/3600;
run;
HOUR=-3
Also, the 24-hour clock is the way to go.
DATA TEMP;
INPUT D_TIME:time.;
FORMAT D_TIME midnight timeampm. Time_diff_midnight hhmm8.;
hr=hour(D_TIME);
%LET mid_night= %SYSFUNC(HMS(24,00,00));
midnight= &mid_night;
IF hr>=12 THEN Time_diff_midnight= D_TIME-&mid_night;
ELSE Time_diff_midnight=D_TIME;
CARDS;
12:30pm
11:10am
12:10am
5:10am
2:30pm
6:30pm
11:58pm
12:01am
;
RUN;
PROC PRINT DATA=TEMP;
Thank you, everyone. I figured out something similar to one of the proposed solutions--thankfully they match up!
proc sql;
create table survey as
select participant_id,
fallaslp,
fallaslpampm,
case
when fallaslpampm = 1 then fallaslp/3600
when fallaslpampm = 2 then (fallaslp - 60*60*12)/3600
end as fallaslp_newtime
from mydata
;
quit;
Are you ready for the spotlight? We're accepting content ideas for SAS Innovate 2025 to be held May 6-9 in Orlando, FL. The call is open until September 16. Read more here about why you should contribute and what is in it for you!
Learn how use the CAT functions in SAS to join values from multiple variables into a single value.
Find more tutorials on the SAS Users YouTube channel.
Select SAS Training centers are offering in-person courses. View upcoming courses for: