Changing the date format in r with strptime and as.Date

Question

Following is part of my data:

       Date        Elev Temp.C 
1 02 January 2010  200   14.7
2 02 January 2010  300    5
3 02 January 2010  500    -2
4 02 January 2010 1000   -9.8
5 02 January 2010 2000   -7.1

I wanted to change the format of the date in to 2010-01-01 or "%Y-%m-%d". Class of data is character and I tried as follows:

data$Date<-as.Date(data$Date,format="%d%B%Y")

data$Date<-as.Date(data[["Date"]],"%d%B%Y")

data$Date<-strptime(data$Date,"%d%B%Y")

All of the above trials are displaying <NA>in the Date column. I have another data file with date format of "%m/%d/%Y", it worked fine with strptime, but for the above data set it is not working. Any idea?

@ZheyuanLi I already tried to with my actual data but it didn't work. I am still getting `NA` — G1124E, Jul 02 '16 at 21:13
@ZheyuanLi . Yes, the space was the problem. I didn't leave space, so that was the cause of the problem. Thank you. — G1124E, Jul 02 '16 at 21:23
@ZhenyuanLi Go ahead, you can put it with description! Thanks. — G1124E, Jul 02 '16 at 21:25

score 1 · Accepted Answer · answered Jul 02 '16 at 21:27

The problem is related to your locale. If you look at ?strptime, you will see:

 ‘%B’ Full month name in the current locale.  (Also matches
      abbreviated name on input.)

This means, %B is sensitive to your locale. Have a look at ?locales if you are unsure what a locale is. When I asked you about the output of Sys.getlocale("LC_TIME"), you said you got "English_United States.1252". Now let's first change your locale:

Sys.setlocale("LC_TIME", "C")

Then do:

as.Date("02 January 2010", "%d %B %Y")
# [1] "2010-01-02"

Note, since there is an empty space between "02", "January" and "2010", you need to leave an empty space between %d, %B, %Y. So, don't use "%d%B%Y" as put in your post, but use "%d %B %Y".

Changing the date format in r with strptime and as.Date

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