Show us the output, don’t just tell us what you are seeing. If the dates are correct in the csv file, show us the structure of the data frame you created with read.csv() and show the command(s) you used to convert the character data to date format. The solution is likely to be simple if you will cut/paste the R console and not just describe what is happening.
David C From: Shivi Bhatia [mailto:shivipm...@gmail.com] Sent: Tuesday, July 26, 2016 10:08 AM To: David L Carlson Subject: Re: [R] Date Time in R Hi David, This gives the results accurately. The first line shows all the variable names and the rest shows all values stored for each of the variable. Here date is appearing as correct. Thanks, Shivi On Tue, Jul 26, 2016 at 7:39 PM, David L Carlson <dcarl...@tamu.edu<mailto:dcarl...@tamu.edu>> wrote: What does this produce? > readLines("YourCSVfilename.csv", n=5) If the data are in Excel, the date format used in .csv files is not always in the same as the format used when viewing dates in the spreadsheet. ------------------------------------- David L Carlson Department of Anthropology Texas A&M University College Station, TX 77840-4352 -----Original Message----- From: R-help [mailto:r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org>] On Behalf Of Shivi Bhatia Sent: Tuesday, July 26, 2016 7:42 AM To: Marc Schwartz Cc: R-help Subject: Re: [R] Date Time in R Thanks Marc for the help. this really helps. I think there is some issue with the data saved in csv format for this variable as when i checked: str(eir$date)- this results in :- Date[1:5327], format: NA NA NA NA NA. Thanks again. On Tue, Jul 26, 2016 at 5:58 PM, Marc Schwartz <marc_schwa...@me.com<mailto:marc_schwa...@me.com>> wrote: > Hi, > > That eir$date might be a factor is irrelevant. There is an as.Date() > method for factors, which does the factor to character coercion internally > and then calls as.Date.character() on the result. > > Using the example data below: > > eir <- data.frame(date = c("05-30-16", "05-30-16", "05-30-16", > "05-30-16", "05-30-16", "05-30-16")) > > > str(eir) > 'data.frame': 6 obs. of 1 variable: > $ date: Factor w/ 1 level "05-30-16": 1 1 1 1 1 1 > > > eir > date > 1 05-30-16 > 2 05-30-16 > 3 05-30-16 > 4 05-30-16 > 5 05-30-16 > 6 05-30-16 > > eir$date <- as.Date(eir$date, format = "%m-%d-%y") > > > str(eir) > 'data.frame': 6 obs. of 1 variable: > $ date: Date, format: "2016-05-30" ... > > > eir > date > 1 2016-05-30 > 2 2016-05-30 > 3 2016-05-30 > 4 2016-05-30 > 5 2016-05-30 > 6 2016-05-30 > > eir$days <- weekdays(eir$date) > > > str(eir) > 'data.frame': 6 obs. of 2 variables: > $ date: Date, format: "2016-05-30" ... > $ days: chr "Monday" "Monday" "Monday" "Monday" ... > > > eir > date days > 1 2016-05-30 Monday > 2 2016-05-30 Monday > 3 2016-05-30 Monday > 4 2016-05-30 Monday > 5 2016-05-30 Monday > 6 2016-05-30 Monday > > > I would check to be sure that you do not have any typos in your code. > > Regards, > > Marc Schwartz > > > > On Jul 26, 2016, at 6:58 AM, Shivi Bhatia > > <shivipm...@gmail.com<mailto:shivipm...@gmail.com>> wrote: > > > > Hello Again, > > > > While i tried your solution as you suggested above it seems to be > working. > > Here is the output > > temp<- dput(head(eir$date)) > > c("05-30-16", "05-30-16", "05-30-16", "05-30-16", "05-30-16", "05-30-16") > > however it still shows class(eir$date) as character and hence i cannot > find > > weekdays from this variable. > > > > Sorry but i still dont understand in totality how R reads dates even > though > > have tried enough. > > > > Regards, Shivi > > > > > > On Tue, Jul 26, 2016 at 5:12 PM, Shivi Bhatia > > <shivipm...@gmail.com<mailto:shivipm...@gmail.com>> > wrote: > > > >> Thanks Duncan for the quick response. I will check again as you > suggested. > >> If that doesn't work i will share a reproducible example. > >> > >> Thanks again!!!! > >> > >> On Tue, Jul 26, 2016 at 4:43 PM, Duncan Murdoch < > murdoch.dun...@gmail.com<mailto:murdoch.dun...@gmail.com>> > >> wrote: > >> > >>> On 26/07/2016 7:05 AM, Shivi Bhatia wrote: > >>> > >>>> Hi Team, > >>>> > >>>> This scenario may have come across a number of times however i checked > >>>> nabble & SO and couldn't find a solution hence request assistance. > >>>> > >>>> I have a date variable in my data-set eir. The class of this var was > >>>> character while i had read the file in r studio. Example of date - > >>>> 05-30-16 > >>>> > >>>> To change this i have used eir$date<- as.Date(eir$date, "%m-%d-%y"). > This > >>>> converts it to a date variable. However when i check few obs > >>>> with head(eir$date) all the results are <NA>. > >>>> > >>> > >>> I think you don't have character data like that, because I see > >>> > >>>> as.Date("05-30-16", "%m-%d-%y") > >>> [1] "2016-05-30" > >>> > >>> I'd guess eir$date is really a factor, because character data is > >>> frequently changed to factor automatically. If that's the case, this > >>> should work for the conversion: > >>> > >>> as.Date(as.character(eir$date), "%m-%d-%y") > >>> > >>> If that doesn't work, you'll need to post something reproducible. > >>> > >>> Duncan Murdoch > >>> > >>> I also need to create weekdays from this date variable but until i get > >>>> this > >>>> resolved i cant find a weekday. For weekday i have used: > >>>> eir$week<- (eir$date) > >>>> eir$week<- weekdays(as.Date(eir$week)) > >>>> class(eir$week) > >>>> eir$week<- as.factor(eir$week) > >>>> head(eir$week) > >>>> > >>>> Head of this eir$week results again as expected in <NA> but shows > Levels: > >>>> Friday Monday Saturday Sunday Thursday Tuesday Wednesday > >>>> > >>>> Not sure what i should do here. Kindly suggest. > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org<mailto:R-help@r-project.org> mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help<https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailman_listinfo_r-2Dhelp&d=CwMFaQ&c=ODFT-G5SujMiGrKuoJJjVg&r=veMGHMCNZShld-KX-bIj4jRE_tP9ojUvB_Lqp0ieSdk&m=s9RjgM0-LqObg32B_ODUoHMjaBJSYFn0ccxorF0VRaQ&s=-2AvIVGKBvHIg4b3KBUCarOh98Mq95XbBM6rQR5o_Qw&e=> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.R-2Dproject.org_posting-2Dguide.html&d=CwMFaQ&c=ODFT-G5SujMiGrKuoJJjVg&r=veMGHMCNZShld-KX-bIj4jRE_tP9ojUvB_Lqp0ieSdk&m=s9RjgM0-LqObg32B_ODUoHMjaBJSYFn0ccxorF0VRaQ&s=Ldb33UyU9KMUXEsxxzwItyCFjZInukICij2jo66xaKg&e=> and provide commented, minimal, self-contained, reproducible code. 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