How to convert SPSS date data to dates?
On Thu, 16 Feb 2006, Peter Dalgaard wrote:
"Jonathan Williams" <jonathan.williams at pharmacology.oxford.ac.uk> writes:
Dear R Helpers, I have imported an SPSS file that contains date data. The data appear in R in a numeric format, as follows: 10485849600 10477641600 10561104000 10562745600 etc. I'd be extremely grateful if someone could tell me how to make these numbers into comprehensible dates!
c(10485849600,10477641600,10561104000,10562745600)+ISOdate(1582,10,14)
[1] "1915-01-26 13:00:00 CET" "1914-10-23 13:00:00 CET" [3] "1917-06-15 13:00:00 CET" "1917-07-04 13:00:00 CET" Does this look right? (If you don't want the times, use as.Date). BTW: There's a strange asymmetry:
ISOdate(1582,10,14)+ c(10485849600,10477641600,10561104000,10562745600)
[1] "1915-01-26 12:00:00 GMT" "1914-10-23 12:00:00 GMT" [3] "1917-06-15 12:00:00 GMT" "1917-07-04 12:00:00 GMT" (have we seen this before?).
Yes, and the second is correct. Timezones are taken from the lhs in +.POSIXt. (That could probably now safely be changed.)
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595