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rdatedate-conversion

Date issue in R

I have some data, for example:

Date        CAC Index
2014-10-10  4073,71
2014-10-17  4033,18
2014-10-24  4128,9

But when I put it into R with XLConnect library I get the following:

wb<-loadWorkbook(file.choose())

lp<-getSheets(wb)
data=lapply(seq_along(lp),function(i) readWorksheet(wb,sheet=lp[i],startRow=1))[[1]]
data[,1]=as.character(data[,1])

tail(data,3)[,c(1,4)]
                   Date CAC.Index
719 2014-10-09 22:00:00   4073.71
720 2014-10-16 22:00:00   4033.18
721 2014-10-23 22:00:00   4128.90

Why don't I get the same dates? In example: I dont get 2014-10-24, instead I get 2014-10-23 22:00:00

Might it be an issue with 

ttz<-Sys.getenv('TZ')
Sys.setenv(TZ='GMT')

? Best regards

Solution

  • I think it comes from importing data as GMT and converting it to your local timezone, which seems to GMT-2, therefore 2014/10/10 00:00 is set to 2014/10/09 22:00.

    Maybe you could solve this by specifying your tz according to OlsonNames() list or specify your date column is Date instead of POSIXct.