Thanks, all, for your time and your very helpful ideas!

On Fri, Jan 13, 2012 at 12:18 PM, Terjeson, Mark <Mterjeson@russell.com>wrote:

> Hi Mary, > > Checking formats is one aspect you can entertain. > > Another aspect you might entertain actually covers > two bases instead of just one. > > A little background: as you know already, date variables > and and datetime variables are exactly the same kind of > variable, a numeric number. The variable isn't different, > but the cosmetics to apply to the final output can be > different. Since date is the number of days since 1jan1960 > and datetime is the number of seconds since 1jan1960, then > the only difference in the numeric variable contents is > that date is usually a 4 or 5 digit number and a datetime > is usually a 9 or 10 digit number. And we can manual convert > the value-range by changing date to datetime (in other words > days to seconds) by merely multiplying the days by the > number seconds in a day(24*60*60 or 86400) > e.g. datetime = date*86400; > conversely > date = datepart(datetime); > or date = int(datetime/86400)); > > Now after reminding all readers about this, we can make > use of this information to cover two bases. > > > Base#1 - ...now I know you state you just need to know if the > variable is date or datetime and you could treat > the entire column as one or the other... This > can indeed be done IF the variable has a format > applied to it, yes, you could check the format. > > However, what if there is NO date-format applied to > your variable? It still could have a format applied > which is just a number format, or there could be NO > format at all? Sometimes people's app may not apply > the cosmetic format until the last minute, and when > need to do your testing and conversions may be sooner > when there is NO format. > > Base#2 - not very often, but you do see externally imported > data have varying date or datetime values in the > same date variable you are reading in. When this > happens you want be able to detect if it is date > or datetime not just at the column level but at > the row level. You want to fold the mix of date > and datetime values to, just date only, or just > datetime only. > > > So, for BOTH scenarios of mixed-values or a variable with > NO format applied, we can use our knowledge of dates to key > from. With only two caveats to rule out, 1) if we don't care > about datetimes just for the morning of one day(1jan1960), > e.g. from 12:00am midnight to 2:12PM on just that one day, > and 2) we assume your program doesn't need to be working > 88 years into the future, then this trick will work for all > SAS versions. > > The trick: If we take '31dec2099'd which merely converts > to a constant integer value of 51134, that does two things > for us. It is just the seconds in the morning of 1jan1960 up to > 2:12PM, and it takes days up through the end of year 2099. > > So if we want to check our incoming variable which; > - does not have a format > or - has mixed date type values > > then, just checking our incoming variable against the value > of 51134 or '31dec2099'd will tell us: > < 51134 is a date value > > 51134 is a datetime value > > > So your sample code of > <code> > format date date9.; > if format(datetime) ='DATETIME' then date=datepart(datetime); > else date=datetime; > <more code> > > could be > > <code> > format date date9.; > if datetime gt '31dec2099'd then date=datepart(datetime); > else date=datetime; > <more code> > > > and that would work whether your incoming variable has a > format or not. (and as another benefit it works for mixed > types if you should ever need that too) > > > > > Hope this is helpful. > > > Mark Terjeson > Investment Business Intelligence > Investment Management & Research > Russell Investments > 206-505-2367 > > > Russell > Global Leaders in Multi-Manager Investing > > > > > > > > > > > > > -----Original Message----- > From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of Mary > Rosenbloom > Sent: Friday, January 13, 2012 11:17 AM > To: SAS-L@LISTSERV.UGA.EDU > Subject: Trouble with the Datepart Function > > Hi all, > > I have a macro that contains a data step, and that datastep uses the > DATEPART function. It looks something like this: > > <code> > format date date9.; > date=datepart(datetime); > <nore code> > > where DATE is a date-only variable, and DATETIME is usually a datetime > variable. > > However, sometimes DATETIME is acutally just a date variable, and when it > is, DATE takes the value of zero. > > QUESTION: is there a function that I can use to determine whether or not > DATETIME is truely a datetime variable, and then conditionally process > only those, such as: > > <code> > format date date9.; > if format(datetime) ='DATETIME' then date=datepart(datetime); > else date=datetime; > <more code> > > I'm using 9.1.3 for the next few days, then 9.3. > > Thanks in advance for your assistance! > > Cheers, > Mary R. >

-- Cheers, Mary F. O. Rosenbloom http://www.sascommunity.org/wiki/User:Otterm1