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")