Convert R date from 1/1/2016 to 01/01/2016

Question

I have found multiple posts that go from 01/01/2016 to 1/1/2016. I would like to go the other way.

Here is my data set

Date    duration   flavor    newDate 
6/4/2016    38  amd64chk    4/6/2016
6/3/2016    873 amd64chk    3/6/2016
6/3/2016    173 amd64chk    3/6/2016
6/3/2016    3383    amd64chk    3/6/2016
6/1/2016    665 amd64chk    1/6/2016
5/26/2016   665 amd64chk    NA
5/25/2016   665 amd64chk    NA
5/24/2016   147 amd64chk    NA
5/24/2016   733 amd64chk    NA
5/24/2016   249 amd64chk    NA

There are two issues here:

1. The date is only converted when the date is in 1/1/2016 format, once the length increases my code stops working

2. the type of each column is different. Date is "factor" and newDate is "POSIXt"

Code

df_amd64chk$newDate <- strptime(as.character(df_amd64chk$Date), "%d/%m/%Y")

I am rather new to R, so my apologies if this isn't well stated. Thanks in advance.

Answer 1

The code you provided is almost correct. You may want to try this small modification:

df_amd64chk$newDate <- as.Date(df_amd64chk$Date,"%m/%d/%Y")

Note that the order of %m and %d is reversed with respect to the code posted in the OP.

If you aren't interested in preserving a Date class, you can convert the output in a character string with another format:

df_amd64chk$newDate <- format(as.Date(df_amd64chk$Date,"%m/%d/%Y"),"%m/%d/%Y")

This will restore almost the original format, but it will add leading zeros where the month or the day have only one digit.