[SOLVED] Change to standard date format with different incoming date formats

Change to standard date format with different incoming date formats

I wish to change my dates to a standard format of dd-mm-yyyy but my issue is that I receive my dates in different formats, for example I wish to change the following dates, and I wish to use the earliest date as a start date not the date range.

myDates = c("25 - 27 February 2025", "25 February - 1 March 2025")

Separately this is not a problem as I can just gsub what I don't want and then change the format using the following line; format(strptime(gsub(" - [0-9]+", "", myDates[1]), "%d %B %Y"), "%d-%m-%Y")

However I'm not able to expand this to deal with both formats

Solution

You could extract the individual date components and then paste them back together. The stringr package is handy here:

library(stringr)

format(
  strptime(
    paste(str_extract(myDates, "\\d+"),        # Day (first 2-digit number)
          str_extract(myDates, "[A-Z][a-z]+"), # Month (first alphabet)
          str_extract(myDates, "\\d{4}")),     # Year (first 4-digit number)
    format="%d %B %Y"), "%d-%m-%Y")

[1] "25-02-2025" "25-02-2025"