What Is the Best Way to Filter by Date in R?

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What Is the Best Way to Filter by Date in R?, Using the dplyr package in R, you can filter a data frame by dates using the following methods.

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Method 1: After Date Filter Rows

df %>% filter(date_column > '2022-01-01')

Method 2: Filter Rows Before Date

df %>% filter(date_column < '2022-01-01')

Method 3: Filter Rows Between Two Dates

df %>% filter(between(date_column, as.Date('2022-01-20'), as.Date('2022-02-20')))

With the following data frame in R, the following examples explain how to utilize each method in practice.

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Let’s create a data frame

df <- data.frame(day=seq(as.Date('2022-01-01'), by = 'week', length.out=10),
                 sales=c(40, 35, 39, 44, 48, 51, 23, 29, 60, 65))

Now we can view the data frame

df
          day sales
1  2022-01-01   240
2  2022-01-08   335
3  2022-01-15   359
4  2022-01-22   544
5  2022-01-29   548
6  2022-02-05   251
7  2022-02-12   223
8  2022-02-19   529
9  2022-02-26   660
10 2022-03-05   165

Example 1: Filter Rows After Date

To filter for rows in the data frame with a date after 1/25/2022, use the following code.

library(dplyr)

filter for rows with dates after 1/25/2022

df %>% filter(day > '2022-01-25')
        day sales
1 2022-01-29   548
2 2022-02-05   251
3 2022-02-12   223
4 2022-02-19   529
5 2022-02-26   660
6 2022-03-05   165

Each row in the generated data frame has a date that is later than 1/25/2022.

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Example 2: Filter Rows Before Date

To filter for rows in the data frame with a date before 1/25/2022, we can use the following code.

library(dplyr)

Let’s filter for rows with dates before 1/25/2022

df %>% filter(day < '2022-01-25')
        day sales
1 2022-01-01   240
2 2022-01-08   335
3 2022-01-15   359
4 2022-01-22   544

Each entry in the generated data frame has a date that is prior to 1/25/2022.

Example 3: Filter Rows Between Two Dates

To filter for rows in the data frame with a date between 1/20/2022 and 2/20/2022, use the following code.

library(dplyr)

filter for rows with dates between 1/20/2022 and 2/20/2022

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df %>% filter(between(daty, as.Date('2022-01-20'), as.Date('2022-02-20')))
         day sales
1 2022-01-22   544
2 2022-01-29   548
3 2022-02-05   251
4 2022-02-12   223
5 2022-02-19   529

The dates in the rows of the generated data frame range from 1/20/2022 to 2/20/2022.

If none of the ways above work, you may need to use them as.Date() function to convert the dates you’re working with to a recognized date format.

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