How to convert a String to Date in R

问题

Is there any way to convert below string to a standard R date class object?

Date_String = "19th January 2020"

Any pointer appreciated.

回答1:

Lubridate can handle it:

> Date_String <- "19th January 2020"
> lubridate::dmy(Date_String)
[1] "2020-01-19"

回答2:

In base R:

# Make sure your locale is English
Sys.getlocale() # can update with Sys.setlocale(LC_TIME = 'en_US.UTF-8')

# Remove "th", more generally the first sequence of lower-case letters
Date_String <- sub("[a-z]+", "", Date_String)
# Now specify the format for as.Date()
as.Date(Date_String, format = "%d %B %Y")
[1] "2020-01-19"

回答3:

    Date_String <- "19th January 2020"

    # Using BASE R
    Date_String <- sub("st|nd|rd|th", "", Date_String)
    as.Date(Date_String, format = "%d %B %Y")
    #> [1] "2020-01-19"

    # Using Lubridate package
    lubridate::dmy(Date_String)
    #> [1] "2020-01-19"

来源：https://stackoverflow.com/questions/61121486/how-to-convert-a-string-to-date-in-r