R help

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Hi all,



I have a data set
containing dates in the format of m/d/y starting from 1950. I wanted  
to
use standard format of date R uses. So I read the data set in R and
converted it using as.Dates. But for dates from 1950-1968, I have the
following problem.

as.Date("1/1/50","%m/%d/%y",origin="1900/01/01") ="2050-01-01"  
instead of "1950-01-01"

But for dates 1969 onwards it is working fine.

As is documented in ?strptime

%y
Year without century (00?99). On input, values 00 to 68 are prefixed  
by 20 and 69 to 99 by 19 ? that is the behaviour specified by the 2004  
and 2008 POSIX standards, but they do also say ?it is expected that in  
a future version the default century inferred from a 2-digit year will  
change?.

as.Date("1/1/69","%m/%d/%y") = "1969-01-01"

Perhaps some greppingg surgery?

 > as.Date(sub("(.+/.+/)([0-6])", "\\119\\2", "1/1/69"),"%m/%d/%Y")
[1] "1969-01-01"

You have not really described the problem completely .... what is the  
range of dates we need to work with?  Do you have any "1/1/05"  type  
values and if so what century should be assumed?

Can anyone please help me find out the problem?

Thanks
Shant
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