[R] as.date

[Erik Iverson]

> Where does the problem comes from?? Maybe from my sytem date ??

Simply from not reading the options carefully enough, from ?strptime,

      ‘%y’ Year without century (00-99). If you use this on input, which
           century you get is system-specific.  So don't!  Most often
           values 00 to 68 are prefixed by 20 and 69 to 99 by 19 - that
           is the behaviour specified by the 2001 POSIX standard, but it
           does also say ‘it is expected that in a future version of
           IEEE Std 1003.1-2001 the default century inferred from a
           2-digit year will change’.

      ‘%Y’ Year with century.


You want %Y, not %y.