R help - Jun 2024 - Format

HI all,

My
I am trying to convert character date (mm/dd/yy)  to YYYY-mm-dd date
format in one of the columns of my data file.

The first few lines of the data file looks like as follow

 head(Atest,10);dim(Atest)
      ddate
1  19/08/21
2  30/04/18
3  28/08/21
4  11/10/21
5  07/09/21
6  15/08/21
7  03/09/21
8  23/07/18
9  17/08/20
10 23/09/20
[1] 1270076       1

I am using the following different scenarios but none of them resulted
the desired result.

library(data.table)
library(stringr)
library(lubridate)
        Atest$ddate1 <- as.Date((Atest$ddate), format = "%m/%d/%y")
        Atest$ddate2 <- mdy((Atest$ddate))
        Atest$ddate3 <=
as.Date(as.character(Atest$ddate),format="%m/%d/%y")
        Atest$ddate4 <-
as.Date(as.character(Atest$ddate),"%m/%d/%y")
        Atest$ddate5 <- lubridate::mdy(Atest$ddate)
> head(Atest,3)
     ddate     ddate1 ddate2 ddate4 ddate5
1 19/08/21   <NA>   <NA>   <NA>   <NA>
2 30/04/18   <NA>   <NA>   <NA>   <NA>
3 28/08/21   <NA>   <NA>   <NA>   <NA>


Any help why I am not getting the desired result.
Thank you,

?s 21:39 de 09/06/2024, Val escreveu:
> HI all,
> 
> My
> I am trying to convert character date (mm/dd/yy)  to YYYY-mm-dd date
> format in one of the columns of my data file.
> 
> The first few lines of the data file looks like as follow
> 
>   head(Atest,10);dim(Atest)
>        ddate
> 1  19/08/21
> 2  30/04/18
> 3  28/08/21
> 4  11/10/21
> 5  07/09/21
> 6  15/08/21
> 7  03/09/21
> 8  23/07/18
> 9  17/08/20
> 10 23/09/20
> [1] 1270076       1
> 
> I am using the following different scenarios but none of them resulted
> the desired result.
> 
> library(data.table)
> library(stringr)
> library(lubridate)
>          Atest$ddate1 <- as.Date((Atest$ddate), format =
"%m/%d/%y")
>          Atest$ddate2 <- mdy((Atest$ddate))
>          Atest$ddate3 <=
as.Date(as.character(Atest$ddate),format="%m/%d/%y")
>          Atest$ddate4 <-
as.Date(as.character(Atest$ddate),"%m/%d/%y")
>          Atest$ddate5 <- lubridate::mdy(Atest$ddate)
> 
>> head(Atest,3)
>       ddate     ddate1 ddate2 ddate4 ddate5
> 1 19/08/21   <NA>   <NA>   <NA>   <NA>
> 2 30/04/18   <NA>   <NA>   <NA>   <NA>
> 3 28/08/21   <NA>   <NA>   <NA>   <NA>
> 
> 
> Any help why I am not getting the desired result.
> Thank you,
> 
> ______________________________________________
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Hello,

Day is clearly first, format "%m/%d/%y" assumes a month 19 in
19/08/21.
Try

as.Date(Atest$ddate, format = "%d/%m/%y")


Hope this helps,

Rui Barradas


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On 2024-06-09 4:39 p.m., Val wrote:
> HI all,
> 
> My
> I am trying to convert character date (mm/dd/yy)  to YYYY-mm-dd date
> format in one of the columns of my data file.
> 
> The first few lines of the data file looks like as follow
> 
>   head(Atest,10);dim(Atest)
>        ddate
> 1  19/08/21
> 2  30/04/18
Those aren't legal months in the first entry.  Your format looks like it 
should be "%d/%m/%y".

Duncan Murdoch