topic Re: SAS Dates in SAS Procedures

SAS Dates

robertrao — Fri, 19 Jul 2013 21:31:30 GMT

I have two dates.. and i am trying to find the number of days

i was trying two methods and get contrasting results for each

Which of these is the right method????????

date1 (discharge date) date2( surgery date)

03MAY2012:13:39:00.000 02MAY12:15:30:00

/*METHOD1*/

days=date1-date2

days_1=datepart(days); /* gives me days_1= 0 */ post surgery days

/*METHOD2*/

days=datepart(date1)-datepart(date2) /* gives me days= 1 */ post surgery days

Thanks

Re: SAS Dates

ballardw — Fri, 19 Jul 2013 22:26:45 GMT

Method 2 is what I would be using generally.

A third approach if were to make sense for your use would be to get the time interval, such as total hours and turn that into 24-hour periods.

Re: SAS Dates

robertrao — Fri, 19 Jul 2013 22:35:55 GMT

Why Method2: ??????it isnt it over estimating the days?????

Re: SAS Dates

ballardw — Fri, 19 Jul 2013 22:45:34 GMT

For most processes that is 1 calendar day, which usually isn't an overestimation and you mentioned finding days. If you need 24 hour periods instead of calendar days you'll probably need to use the INTCK function to count specified intervals of time.

Re: SAS Dates

robertrao — Fri, 19 Jul 2013 23:16:12 GMT

Hi,

Thanks for the reply,

I also wanted to correct the usage..Is the extra braces needed as in the second case?or firstone is perfectly fine?

days=datepart(date1)-datepart(date2);

days=(datepart(date1)-datepart(date2));

Thanks

Re: SAS Dates

ballardw — Mon, 22 Jul 2013 15:17:29 GMT

Both lines return the same result. The only time you would need the extra braces is in a more complex computation where you need to control the order of operations.