How to Convert Date to Numeric in R?

In this article, we will discuss how to convert date to numeric in R Programming Language.

Method 1: Using as.numeric()

This function is used to convert date into numeric

Syntax:

as.numeric(date)

where the date is the input date.

Example:

data = as.POSIXct("1/1/2021  1:05:00 AM",
                  format="%m/%d/%Y  %H:%M:%S %p")

# display
print(data)

# convert to numeric
print(as.numeric(data))

Output:

[1] "2021-01-01 01:05:00 UTC"
[1] 1609463100

If we want to get the number of days from the number, divide the number by 86400.

as.numeric(date)/86400

If we want to get the number of years from date, then divide it by 365.

as.numeric(date)/86400/365

Example: R program to convert dates into days and years

data = as.POSIXct("1/1/2021  1:05:00 AM", 
                  format="%m/%d/%Y  %H:%M:%S %p")

# display
print(data)

# convert to numeric
print(as.numeric(data))

# convert to numeric and get days
print(as.numeric(data)/86400)

# convert to numeric and get years
print((as.numeric(data)/86400)/365)

Output:

[1] "2021-01-01 01:05:00 UTC"
[1] 1609463100
[1] 18628.05
[1] 51.03574

Method 2: Use functions from lubridate package

Here, By using this module, we can get the day, month, year, hour, minute, and second separately in integer format.

Syntax:

day:
day(date)

month:
month(date)

year:
year(date)

hour:
hour(date)

minute:
minute(date)

second:
second(date)

Example:

# load the library
library("lubridate")

# create date
data = as.POSIXct("1/1/2021  1:05:00 AM", 
                  format="%m/%d/%Y  %H:%M:%S %p")

# display
print(data)

# get the day
print(day(data))

# get the month
print(month(data))

# get the year
print(year(data))

# get the hour
print(hour(data))

# get the minute
print(minute(data))

# get the second
print(second(data))

Output:

[1] "2021-01-01 01:05:00 UTC"
[1] 1
[1] 1
[1] 2021
[1] 1
[1] 5
[1] 0