Hi all, I'm just getting started in R so bear with my newbness. I am trying to create a very simple histogram of logins by time, with data coming in from a MYSQL query. the raw data looks like this: "id" "user_id" "experience_given" "created_at" "ip_aton" "1" XXXXXXX 2445626 0 "2010-01-21 00:00:01" 1123632036 "2" XXXXXXX 2444945 0 "2010-01-21 00:00:01" 1123632036 After searching around for how to deal with the timestamp, I settled with converting to POSIXct, and creating a chron object with as.numeric(). So I managed to replace the timestamps with chron objects. command: bt$created_at = chron(as.numeric(as.POSIXct(bt$created_at))) Seems very roundabout, but gets the job done. I also see that I could just use the numerical value instead, if readability wasn't an issue. The problem is, when I try to hist(bt$created_at), I get errors: Error in axis(2, adj = adj, cex = cex, font = font, las = las, lab = lab, : 'labels' is supplied and not 'at' In addition: Warning messages: 1: In plot.window(xlim, ylim, log = log, ...) : "histo" is not a graphical parameter 2: In title(main = main, sub = sub, xlab = xlab, ylab = ylab, ...) : "histo" is not a graphical parameter and the histogram looks busted like this: http://n4.nabble.com/file/n1294762/picture236.png Any ideas? I'm quite lost here, and having trouble finding date-time specific info. I do get the gist that chron is supposed to be the key, but I'm having a hard time understanding an overview of all the different time related classes. thnx for any advice in advance. -- View this message in context: http://n4.nabble.com/newb-question-chron-and-hist-tp1294762p1294762.html Sent from the R help mailing list archive at Nabble.com.