Date

The Date class provides methods for working with calendar dates in Ruby. It’s part of the standard library and offers powerful date manipulation and parsing capabilities.

Overview

Ruby’s Date class represents dates without times:

• Create: Generate dates from strings, components, or today
• Parse: Convert strings into Date objects
• Manipulate: Add, subtract, and calculate date differences
• Format: Display dates in various formats

Creating Date Objects

Today’s Date

Date.today      # => #<Date: 2026-03-13>
Date.today.to_s # => "2026-03-13"

From String

require "date"

Date.parse("2026-03-13")
# => #<Date: 2026-03-13>

Date.parse("March 13, 2026")
# => #<Date: 2026-03-13>

From Components

Date.new(2026, 3, 13)
# => #<Date: 2026-03-13>

From Time

DateTime.now.to_date
Time.now.to_date

Date Components

You can extract individual components from a Date object:

date = Date.today

date.year      # => 2026
date.month     # => 3
date.day       # => 13
date.wday      # => 5 (0 = Sunday)
date.yday      # => 72 (day of year)
date.leap?     # => false

Date Calculations

Adding/Subtracting Days

date = Date.today

date + 1       # Tomorrow
date - 7       # One week ago
date + 30      # About one month later

Date Differences

date1 = Date.new(2026, 1, 1)
date2 = Date.new(2026, 3, 13)

(date2 - date1).to_i   # => 71 days

Comparing Dates

past = Date.new(2020, 1, 1)
future = Date.new(2030, 1, 1)

future > past      # => true
past <=> future    # => -1 (past is earlier)
past == past       # => true

Date Ranges

Iterating Over Dates

start = Date.new(2026, 3, 10)
finish = Date.new(2026, 3, 15)

(start..finish).each do |date|
  puts date
end
# 2026-03-10
# 2026-03-11
# 2026-03-12
# 2026-03-13
# 2026-03-14
# 2026-03-15

Checking Range Inclusion

range = Date.new(2026, 1, 1)..Date.new(2026, 12, 31)

range.include?(Date.new(2026, 6, 15))  # => true
range.include?(Date.new(2027, 1, 1))   # => false

Date Formatting

strftime

The strftime method formats dates using directives:

date = Date.today

date.strftime("%Y-%m-%d")      # => "2026-03-13"
date.strftime("%d/%m/%Y")      # => "13/03/2026"
date.strftime("%B %d, %Y")     # => "March 13, 2026"
date.strftime("%A")            # => "Friday"

Directive	Meaning	Example
%Y	Year	2026
%m	Month (01-12)	03
%d	Day	13
%A	Weekday	Friday
%B	Month name	March

Predefined Formats

date = Date.today

date.iso8601     # => "2026-03-13"
date.rfc2822     # => "Fri, 13 Mar 2026 00:00:00 +0000"

Date Calculations

Month Navigation

date = Date.new(2026, 3, 13)

date >> 1        # => 2026-04-13 (next month)
date << 1        # => 2026-02-13 (previous month)

Finding Day of Week

date = Date.new(2026, 3, 13)

date.monday?     # => false
date.friday?    # => true
date.sunday?    # => false

Beginning/End of Month

date = Date.new(2026, 3, 13)

date.beginning_of_month  # => 2026-03-01
date.end_of_month        # => 2026-03-31

Parsing Dates

Flexible Parsing

require "date"

Date.parse("2026-03-13")           # => 2026-03-13
Date.parse("03/13/2026")           # => 2026-03-13
Date.parse("13-Mar-2026")          # => 2026-03-13

With Format

require "date"

Date.strptime("13-03-2026", "%d-%m-%Y")
# => 2026-03-13

Practical Examples

Days Until Event

event = Date.new(2026, 12, 25)
today = Date.today

days_until = (event - today).to_i
puts "Days until Christmas: #{days_until}"

Week Number

date = Date.new(2026, 3, 13)

date.cweek     # => 11 (ISO week number)
date.cwyear    # => 2026 (ISO week year)

Day of Year

date = Date.new(2026, 3, 13)

date.yday      # => 72 (day 72 of the year)

See Also

• Time — for working with dates and times together
• File — for file timestamp operations