DateByExample

Provides a Ruby implementation of Go-style date formatting by example

Add this line to your application's Gemfile:

gem 'date_by_example'

And then execute:

$ bundle

Or install it yourself as:

$ gem install date_by_example

This gem adds a by_example method to Date, Time, and DateTime.

The argument to this method is the formatted version of a reference date.

For example:

> d = Date.today
> d.by_example("2006-01-02")   => "2018-06-11"

> t = DateTime.now
> t.by_example("Jan 02 2006 @ 3:04 pm")  => "Jun 11 2018 @ 3:52 pm"

> t = Time.now
> t.by_example("Jan 02 2006 @ 3:04 pm")  => "Jun 11 2018 @ 3:53 pm"

The reference date is Jan 2, 2006 at 3:04:05 PM MST, which can be remembered as 1 2 3 4 5 6 -7.

I realize that remembering the reference date is not the easy part, but I think it's easier than remembering all the strftime format strings

• Year: 2006 and 06 (but not Ruby's %c for the century)
• Month: January, JANUARY, Jan, JAN, 1, and 01, but not " 1" for space padding
• Day: 2, 02, 002 (for day of year), Monday, MONDAY, Mon, MON, but not " 2" for space padding
• Hour: 15, 3, pm, PM
• Minute: 04
• Second: 05, 05.000 for milliseconds and 05.000000 and 05.000000000
• Time Zone: -7000, -07:00, -07:00:00, MST

This does not support Ruby's week based formats

The slow part of using this gem is generating the format string from the example, if you want to reuse a format multiple times, you can do so by creating and reusing an ExampleFormatter

> ef = ExampleFormatter.new("01/02/06")
> ef.format(Date.today)   => "06/11/18"
> ef.format(Time.now)     => "06/11/18"

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/date_by_example. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the DateByExample project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.