R How to convert date format

Question

I was looking to convert the following character string in a date format:

string <- '22APR2020'
date <- as.Date(string, format='%d%b%y')
date
>>> NA

Unfortunately, the result is NA and I need to convert it as a date in order to being able to calculate the time between two dates.

Thanks you

Seems like a locale issue. Check [strptime, as.POSIXct and as.Date return unexpected NA](https://stackoverflow.com/questions/13726894/strptime-as-posixct-and-as-date-return-unexpected-na) — Henrik, Jun 16 '20 at 12:28

score 3 · Answer 1 · answered Jun 16 '20 at 12:23

3

You could use the anytime package:

library(anytime)
string <- '22APR2020'
anytime::anydate(string)
[1] "2020-04-22"

answered Jun 16 '20 at 12:23

Ahorn

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I am not sure which one between anytime and lubridate package is the most maintained over time. Right now, your answer is valid. Which one would you recommend? – John E. Jun 16 '20 at 13:17

score 1 · Answer 2 · answered Jun 16 '20 at 12:29

The problem is your locale setting. It probably is set to a language where the fourth month is not abbreviated as "APR".

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

string <- '22APR2020'
as.Date(string, format='%d%b%Y')
#[1] NA

Sys.setlocale("LC_TIME", "German")
as.Date(string, format='%d%b%Y')
#[1] "2020-04-22"

Also, note the capital Y is used in the format string. It's important. y only refers to the decade (it would give the same result, by chance, for 2020, but give the wrong result for 2021).

score 1 · Accepted Answer · answered Jun 16 '20 at 12:42

1

When in doubt always use lubridate:

string <- '22APR2020'
library(lubridate)
dmy(string)
[1] "2020-04-22"

here dmy is order of date, month and year appearance.

answered Jun 16 '20 at 12:42

Harshal Gajare

605
4
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R How to convert date format

3 Answers3