This might be what you are looking for. It uses with.ffdf from package ffbase. require(ffbase) y_in_ffdf$dateval <- with(y_in_ffdf, as.Date(dateval) ) Jan -- View this message in context: http://r.789695.n4.nabble.com/convert-ff-vector-object-into-as-Date-tp4647753p4647764.html Sent from the R help mailing list archive at Nabble.com.