Re: [R] Using Aggregate for Date

Phil, Thanks a lot, it works well. -- View this message in context: http://r.789695.n4.nabble.com/Using-Aggregate-for-Date-tp3265417p3265469.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://st

Re: [R] Using Aggregate for Date

Belle - Assuming that by=list(mydata$schoolid, mydata$year) was a typo and should have been by=list(mydata$studentid, mydata$year), setting class(day_min$x) = 'POSIXct' day_min$x = format(day_min$x,'%m/%d/%y %l:%M %p') should make the mininum days display in the format you want.

[R] Using Aggregate for Date

Hi, I am trying to find the min of day for each student in each year. Here is the dataset: date studentid year 1/1/05 6:07 AM 236 20082009 3/27/09 9:45 AM 236 20082009 4/29/09 8:44 AM 236 20082009 3/27