How to Create a Ruby Date Object from a String

How do I create a Ruby date object from a string?

Date.parse('31-12-2010')

Alternatively Date#strptime(str, format).

converting a hash string into a date object ruby

Handle Both Standard and Custom Date Strings

Date#parse doesn't handle arbitrary strings in all cases. Even when it does, it may not handle them the way you expect. For example:

parse_date "1/1/18"
#=> #<Date: 2001-01-18 ((2451928j,0s,0n),+0s,2299161j)>

While Date#parse handles many date formats automagically, it only successfully parses objects that match its internal expectations. When you have multiple or arbitrary date formats, you have to define your own date specifications using Date#strptime to handle those formats that Date#parse doesn't understand, or that it handles incorrectly. For example:

require 'date'

def parse_date str
  Date.parse str
rescue Date::Error
  case str
  when /\A\d{4}\z/
    Date.strptime str, '%Y'
  when /\A\d{2}\z/
    Date.strptime str, '%y'
  else
    raise "unexpected date format: #{str}"
  end
end

date_samples = ["July 11th 1960", "September 1988", "1776"]

date_samples.map { |date| parse_date(date) }
#=> [#<Date: 1960-07-11 ((2437127j,0s,0n),+0s,2299161j)>, #<Date: 1988-09-01 ((2447406j,0s,0n),+0s,2299161j)>, #<Date: 1776-01-01 ((2369731j,0s,0n),+0s,2299161j)>]

This obviously is not an exhaustive list of potential formats, but you can add more examples to date_samples and update the case statement to include any unambiguous date formats you expect from your data set.

Convert string to datetime ruby on rails

You can use DateTime to parse the date from a specific format.

if the format you are looking to parse is "03/28/2018 1:46 AM" then you can do this.

date = DateTime.strptime('03/28/2018 1:46 AM', '%m/%d/%Y %I:%M %p')

# date to ISO 8601

puts date.to_time
# output: 2018-03-28 07:16:00 +0530

puts date.strftime("%m/%d/%Y")
# output: 03/28/2018

Date formats:

Date (Year, Month, Day):

%Y - Year with century (can be negative, 4 digits at least)
        -0001, 0000, 1995, 2009, 14292, etc.
%m - Month of the year, zero-padded (01..12)
        %_m  blank-padded ( 1..12)
        %-m  no-padded (1..12)
%d - Day of the month, zero-padded (01..31)
        %-d  no-padded (1..31)

Time (Hour, Minute, Second, Subsecond):

%H - Hour of the day, 24-hour clock, zero-padded (00..23)
%k - Hour of the day, 24-hour clock, blank-padded ( 0..23)
%I - Hour of the day, 12-hour clock, zero-padded (01..12)
%l - Hour of the day, 12-hour clock, blank-padded ( 1..12)
%P - Meridian indicator, lowercase (``am'' or ``pm'')
%p - Meridian indicator, uppercase (``AM'' or ``PM'')

%M - Minute of the hour (00..59)

You can refer to all formats here.

How can I create a new Date instance in Ruby

According to Date documentation:

require 'date'

Date.new(2001,2,25)           #=> #<Date: 2001-02-25 
Date.jd(2451966)             #=> #<Date: 2001-02-25 
Date.ordinal(2001,56)        #=> #<Date: 2001-02-25 
Date.commercial(2001,8,7)    #=> #<Date: 2001-02-25 
Date.parse('2001-02-25')     #=> #<Date: 2001-02-25 
Date.strptime('25-02-2001', '%d-%m-%Y') #=> #<Date: 2001-02-25 
Time.new(2001,2,25).to_date   #=> #<Date: 2001-02-25 

convert String to DateTime

DateTime.strptime allows you to specify the format and convert a String to a DateTime.

Ruby String to Date Conversion

What is wrong with Date.parse method?

str = "Tue, 10 Aug 2010 01:20:19 -0400 (EDT)"
date = Date.parse str
=> #<Date: 4910837/2,0,2299161>
puts date
2010-08-10

It seems to work.

The only problem here is time zone. If you want date in UTC time zone, then it is better to use Time object, suppose we have string:

str = "Tue, 10 Aug 2010 01:20:19 +0400"
puts Date.parse str
2010-08-10
puts Date.parse(Time.parse(str).utc.to_s)
2010-08-09

I couldn't find simpler method to convert Time to Date.

Ruby - convert string to date

For Ruby 1.9.2:

require 'date'    # If not already required. If in Rails then you don't need this line).
puts DateTime.parse("2011-06-02T23:59:59+05:30").to_date.to_s

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