Rolf, I tried the same thing at first, and got the same error. So I suspect Anna didn't really use that code either. :-)
Dan Daniel J. Nordlund Washington State Department of Social and Health Services Planning, Performance, and Accountability Research and Data Analysis Division Olympia, WA 98504-5204 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of Rolf Turner > Sent: Thursday, March 25, 2010 3:09 PM > To: Joshua Wiley > Cc: r-help@r-project.org > Subject: Re: [R] Convert number to Date > > > > Kind of off the thread a bit, but when I do: > > > as.Date(40182) > > I ***do not*** get "2080-01-06". Instead I get an error: > > Error in as.Date.numeric(40182) : 'origin' must be supplied > > Am I the only user who gets picked on in this way, or does it > happen to others as well? The help on as.Date() clearly specifies > that "origin" must be supplied. So how come Anna got the result that > she did? > > > sessionInfo() > R version 2.10.1 (2009-12-14) > i386-apple-darwin8.11.1 > > locale: > [1] en_NZ.UTF-8/en_NZ.UTF-8/C/C/en_NZ.UTF-8/en_NZ.UTF-8 > > attached base packages: > [1] datasets utils stats graphics grDevices methods base > > other attached packages: > [1] misc_0.0-12 fortunes_1.3-7 MASS_7.3-4 > > cheers, > > Rolf Turner > > On 26/03/2010, at 9:47 AM, Joshua Wiley wrote: > > > Dear Anna, > > > > Rolf's explanation not withstanding, it has to do with differences in > > how R and Excel treat dates. If you use > > > > as.Date(40182, origin="1899-12-30") > > > > you will get the same date as Excel. You can look at: > > > > > http://office.microsoft.com/training/training.aspx?AssetID=RC102786151033&CTT= > 6&Origin=RP102786121033 > > > > For an official guide on how Excel dates are calculated. Apparently, > > Excel's calendar starts on 1 January 1900. Why one has to use an > > origin of 30 December 1899 in R...well, I suspect that gets back to > > Rolf's explanation. > > > > > > HTH, > > > > Josh > > > > On Thu, Mar 25, 2010 at 1:33 PM, anna <lippelann...@hotmail.com> wrote: > >> > >> Hello, I have a date value in excel: 1/4/2010 which in number format gives > >> me > >> 40182. When I read this with read.xls from R I get same 40182 so what I do > >> is that I use the as.Date() function but here is what the as.Date() > >> function > >> returns me: > >>> as.Date(40182) > >> [1] "2080-01-06" > >> Why don't I get the same thing as in excel? > >> Thanks! > > ################################################################### > ### > Attention: > This e-mail message is privileged and confidential. If you are not the > intended recipient please delete the message and notify the sender. > Any views or opinions presented are solely those of the author. > > This e-mail has been scanned and cleared by MailMarshal > www.marshalsoftware.com > ################################################################### > ### > > ______________________________________________ > 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.