Hi, I have dates as follows: 1/4/2006 0:00:00 AM It is a factor at present. How do I find out the day of the week from this? How do I convert to Julian date format? Thanks. Chetty -- Professor of Family Medicine Boston University Tel: 617-414-6221, Fax:617-414-3345 emails: chettyvk@gmail.com,vchetty@bu.edu [[alternative HTML version deleted]]
Three steps: 1) as.character to get character representation 2) as.POSIXct to convert to time 3) julian() or strptime() to get Julian date. Read the docs (esp on part 2 and 3) to get the format strings just right. Cheers, Michael On Aug 24, 2012, at 10:30 PM, Veerappa Chetty <chettyvk at gmail.com> wrote:> Hi, > I have dates as follows: > 1/4/2006 0:00:00 AM > It is a factor at present. > How do I find out the day of the week from this? How do I convert to Julian > date format? > Thanks. > Chetty > > -- > Professor of Family Medicine > Boston University > Tel: 617-414-6221, Fax:617-414-3345 > emails: chettyvk at gmail.com,vchetty at bu.edu > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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.
HI, Try this: dat1<-"01/04/2006 1:10:60 PM" ?dat1<-as.character(dat1) ?strptime(dat1,"%m/%d/%Y %I:%M:%S %p")$yday+1 #[1] 4 A.K. ----- Original Message ----- From: Veerappa Chetty <chettyvk at gmail.com> To: r-help at r-project.org Cc: Sent: Friday, August 24, 2012 11:30 PM Subject: [R] date Hi, I have dates as follows: 1/4/2006 0:00:00 AM It is a factor? at present. How do I find out the day of the week from this? How do I convert to Julian date format? Thanks. Chetty -- Professor of Family Medicine Boston University Tel: 617-414-6221, Fax:617-414-3345 emails: chettyvk at gmail.com,vchetty at bu.edu ??? [[alternative HTML version deleted]] ______________________________________________ R-help at 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.