For me it owrks when i write it like: as.Date(paste(mydata$Delivery.Date), "%m/%d/%Y") Hope it works, Regards, Ricardo -- View this message in context: http://r.789695.n4.nabble.com/as-date-do-not-know-how-to-convert-mydata-1-to-class-Date-tp4638691p4638696.html Sent from the R help mailing list archive at Nabble.com.