Sure, we could just use a String to represent a date, like "April 19, 1987". But Ruby has a built-in class that makes it much easier to work with dates: Date.

Creating a date

The Date class isn’t loaded into every Ruby program by default, so to use it we first need to say

require "date"

(Usually we omit the parentheses around the string argument to the require method.)

After require "date", we can create a new instance as usual with: # => #<Date: -4712-01-01 ((0j,0s,0n),+0s,2299161j)>

By default, the new date is January 1st, of the year -4712 BCE! Interesting1, but not very helpful.

You can also pass arguments to initialize with a specific year, month, and day:            #=> #<Date: 2001-01-01 ...>,2,3)        #=> #<Date: 2001-02-03 ...>,2,-1)       #=> #<Date: 2001-02-28 ...>

The method returns an object initialized to the current date. # => #<Date: 2019-04-16 ((2458590j,0s,0n),+0s,2299161j)>


The Date.parse() method accepts a String argument and tries to interpret it as a date, initializing a Date object.

Date.parse("2001-02-03") #=> #<Date: 2001-02-03 ...>
Date.parse("20010203") #=> #<Date: 2001-02-03 ...>
Date.parse("3rd Feb 2001") #=> #<Date: 2001-02-03 ...>


You can subtract two dates from one another, which will return the number of days between them. The return value class is a Rational, which can be converted to a regular Integer with .to_i:

number_of_days = - Date.parse("July 4, 1776")
 => (88674/1)
2.6.1 :004 > days.to_i
 => 88674


Returns the day of the month (1-31).

held_on =,2,3)

held_on.mday #=> 3


Returns true if the date is a Monday.


Returns true if the date is a Tuesday.


Returns true if the date is a Wednesday.


Returns true if the date is a Thursday.


Returns true if the date is a Friday.


Returns true if the date is a Saturday.


Returns true if the date is a Sunday.


Returns the day of week (0-6, Sunday is zero).,2,3).wday #=> 6