[R] Convert Character to Date

Bill.Venables at csiro.au Bill.Venables at csiro.au
Tue Mar 31 09:28:46 CEST 2009

If you want the vector to be a Date you need to specify a date at least down to the day.  Otherwise the date is not well defined and becomes <NA> as you noted.

Perhaps the easiest thing is to give it a particular day of the month, e.g. the first, or the 15 (the "ides"), or ...

> x <- as.Date(paste("1990-January", 1, sep="-"), format = "%Y-%B-%d")
> x
[1] 1990-01-01

Now if you want to display the date suppressing the dummy day, you can

> y <- format(x, "%Y-%B")
> y
[1] "1990-January"

Bill Venables

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Bob Roberts
Sent: Tuesday, 31 March 2009 5:14 PM
To: r-help at r-project.org
Subject: [R] Convert Character to Date

   I have a date in the format Year-Month Name (e.g. 1990-January) and R classes it as a character. I want to convert this character into a date format, but when I try as.Date(1990-January, "%Y-%B"), I get back NA. The function strptime also gives me NA back. Thanks.

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