Find Out Number of Days of a Month in R (2 Examples)

In this article, I’ll explain how to get the number of days in a certain month in R.

Table of contents:

Let’s jump right to the R code…

Creation of Example Data

The following data is used as a basement for this R programming tutorial:

my_date <- as.Date("2023-04-10")    # Create example date
my_date                             # Print example date
# [1] "2023-04-10"

As you can see based on the previous output of the RStudio console, our example data is a date object representing the 10th of April in the year 2023.

Example 1: Get Number of Days in a Certain Month Using days_in_month() Function of lubridate Package

The following R syntax demonstrates how to calculate the number of days in a specific month using the lubridate package.

To be able to use the functions of the lubridate add-on package, we first need to install and load lubridate:

install.packages("lubridate")       # Install lubridate package
library("lubridate")                # Load lubridate

Next, we can count the number of days in the month of our date object using the days_in_month function:

days_in_month(my_date)              # Print days in month
# Apr 
#  30

As you can see, the month of our date (i.e. April) has 30 days.

Example 2: Get Number of Days in a Certain Month Using monthDays() Function of Hmisc Package

Alternatively to the lubridate package, we can also use the Hmisc package to get the number of days of a particular month.

In order to use the functions of the Hmisc package, we first have to install and load Hmisc:

install.packages("Hmisc")           # Install & load Hmisc package
library("Hmisc")

Next, we can apply the monthDays function to our date object:

monthDays(my_date)                  # Print days in month
#  30

Once again, the value 30 was returned.

Video & Further Resources

In case you need further explanations on the R programming codes of the present tutorial, I recommend watching the following video on my YouTube channel. I’m explaining the R syntax of this page in the video tutorial:

Furthermore, you might want to have a look at the related R articles on my homepage. Some other articles about topics such as numeric values, indices, and data inspection are listed below.

• Add & Subtract Days to & from Date in R
• Time Difference Between Dates in Weeks, Days, Hours, Minutes & Seconds
• difftime Function in R
• R Programming Language

In summary: In this article you have learned how to find out the number of days in a date object in R programming. In case you have any additional questions, let me know in the comments below.