A sample of my dataframe: date 1 25 February 1987 2 20 August 1974 3 9 October 1984 4 18 August 1992 5 19 September 1995 6 16-Oct-63 7 30-Sep-65 8 22 Jan 2008 9 13-11-1961 10 18 August 1987 11 15-Sep-70 12 5 October 1994 13 5 December 1984 14 03/23/87 15 30 August 1988 16 26-10-1993 17 22 August 1989 18 13-Sep-97 I have a large dataframe with a date variable that has multiple formats for dates. Most of the formats in the variable are shown above- there are a couple of very rare others too. The reason why there are multiple formats is that the data were pulled together from various websites that each used different formats. I have tried using straightforward conversions e.g. strftime(mydf$date,"%d/%m/%Y") but these sorts of conversion will not work if there are multiple formats. I don't want to resort to multiple gsub type editing. I was wondering if I am missing a more simple solution? Code for example: structure(list(date = structure(c(12L, 8L, 18L, 6L, 7L, 4L, 14L, 10L, 1L, 5L, 3L, 17L, 16L, 11L, 15L, 13L, 9L, 2L), .Label = c("13-11-1961", "13-Sep-97", "15-Sep-70", "16-Oct-63", "18 August 1987", "18 August 1992", "19 September 1995", "20 August 1974", "22 August 1989", "22 Jan 2008", "03/23/87", "25 February 1987", "26-10-1993", "30-Sep-65", "30 August 1988", "5 December 1984", "5 October 1994", "9 October 1984"), class = "factor")), .Names = "date", row.names = c(NA, -18L), class = "data.frame")