Extract Day from Date in R (Example)

This post explains how to return only the day of a Date object in R programming.

Table of contents:

Let’s take a look at some R codes in action…

Creation of Exemplifying Data

As a first step, we have to construct some data that we can use in the example code below:

x <- "2022-10-17"                                 # Create example date
x                                                 # Print example date
# "2022-10-17"

The previous output of the RStudio console shows that our example data object contains a character string showing a date (i.e. the 17th of October 2022).

Example: Extracting Day from Date Object Using format() Function

This example explains how to extract the day of a date in R. First, we have to apply the as.Date function to format our input character string to a Date object:

x_formatted <- as.Date(x, format = "%Y-%m-%d")    # Convert character to date
x_formatted                                       # Print Date object
# "2022-10-17"

As you can see, the output looks exactly the same as our input character string. However, the class is different:

class(x_formatted)                                # Check class
# "Date"

Our updated data has the class “Date”.

Now, we can apply the format command to return only the day of our Date object:

x_day <- format(x_formatted, format = "%d")       # Extract day from date
x_day                                             # Print day
# "17"

The day of our Date object is 17.

Video & Further Resources

Would you like to know more about dates in R? Then I can recommend to have a look at the following video of my YouTube channel. I’m explaining the R syntax of this tutorial in the video.

The YouTube video will be added soon.

Furthermore, you may want to have a look at the related tutorials of this homepage. A selection of articles is shown below.

• Extract Month from Date
• Extract Year from Date
• R Programming Examples

In this tutorial you learned how to get the day of a vector of dates in the R programming language. Let me know in the comments section, if you have additional questions. Furthermore, please subscribe to my email newsletter in order to get updates on the newest articles.