I am running into trouble when trying to compare date fields in my dataset. When I view a field, it looks like it is a date in 2011:
> alldata$new.date.local[1] [1] "2011-07-01 12:08:07 EDT" However, when I try to compare it to a character string, it seems to think it is equal to sometime between the years 1310 and 1309 > alldata$new.date.local[1] < "1310-01-01 00:00:00 EDT" [1] TRUE > alldata$new.date.local[1] < "1309-12-31 23:59:59 EDT" [1] FALSE But not exactly equal to midnight of Dec 31 in 1309, so it is not equal to any exact time: > alldata$new.date.local[1] == "1309-12-31 23:59:59 EDT" [1] FALSE > alldata$new.date.local[1] < "1309-12-31 23:59:59 EDT" [1] FALSE > alldata$new.date.local[1] > "1309-12-31 23:59:59 EDT" [1] TRUE Even though this date field was created using as.POSIXct from a text string, I have tried fixing this by reapplying the as.POSIXct function: >alldata$new.date.local <- as.POSIXct(alldata$new.date.local, tz = "EDT") But this does not seem to fix the problem. When I try recreating the date from a character string I get the same behavior. Any suggestions would be much appreciated. -Heather [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.