Hi,
You may try: x1<- c("4/25/71","4/20/64") fun1<- function(x, year){ m1<-as.numeric(format(as.Date(x1,"%m/%d/%y"),"%y")) m1<- ifelse(m1>year%%100,1900+m1,2000+m1) m2<- paste0(gsub("(.*\\/).*$","\\1",x),m1) as.Date(m2,"%m/%d/%Y") } fun1(x1,1950) #[1] "1971-04-25" "1964-04-20" str(fun1(x1,1950)) # Date[1:2], format: "1971-04-25" "1964-04-20" A.K. ----- Original Message ----- From: Frans Marcelissen <frans.marcelis...@digipsy.nl> To: "R-help@r-project.org" <R-help@r-project.org> Cc: Sent: Friday, August 30, 2013 9:12 AM Subject: [R] strange conversion char to date Hi R-friends, Can anyone explain the following strange behavior to me? > as.Date( "4/25/71","%m/%d/%y") [1] "1971-04-25" > as.Date( "4/25/62","%m/%d/%y") [1] "2062-04-25" so 71 is converted to 1971, while 62 is converted to 2062? Does anyone know why? And is there a simple way to specify the date? (does works the same way in R 2.01 as well as in 1.9) ------------------- dr F.H.G. (Frans) Marcelissen DigiPsy (www.DigiPsy.nl <http://www.digipsy.nl/>) Pomperschans 26 5595 AV Leende tel: 040 2065030/06 2325 06 53 skype adres: frans.marcelissen email: frans.marcelis...@digipsy.nl [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.