User Timezone Detector Gem

The user timezone detector Gem lets you attach the detects_timezone trait to your User, Account or Contact classes and auto-populate the timezone field with detected attributes.

Table of Contents

• Installation
• Usage
  • Automatically populating the timezone field
  • Getting the current time for a user, contact or account
  • Compatible Lookup Combinations
  • What if my local class attributes are different?
• Development
• Contributing
• Rate Limits
• License

Add this line to your application's Gemfile:

gem 'user_timezone'

And then execute:

$ bundle

Or install it yourself as:

$ gem install user_timezone

This example assumes you have a table called "contacts" and it has a column with "zip" and "country" or some other compatible lookup combinations (see Compatible Lookup Combinations).

class Contact < ActiveRecord::Base
    detects_timezone log: true, on: :before_safe
end
contact = Contact.new(zip: 78729, country: "US")
contact.save!
puts contact.timezone
# OUTPUT: "America/Chicago"

Continuing on from the previous example, we can now also get the current time for the user.

contact.current_time
# Output: "2016-02-21T16:37:10.064-06:00"

This returns a ruby time object so you can manipulate it whatever way you want. Here's an example where we check to see if the user is awake:

contact_hour = contact.current_time.hour
if (contact_hour > 0 && contact_hour < 8)
    puts "User is still sleeping, don't bother them - it's only #{contact_hour}am their time!"
else
    puts "User is awake, time to party! ┏(-_-)┛ ┗(-_- )┓ ┗(-_-)┛ ┏(-_-)┓ "
end
# OUTPUT (for example if it's 4am for them): User is still sleeping, don't bother them - it's only 4am their time!

The API will accept any parameters and try to make a best guess of what the timezone is, even if the timezone guess will be very inaccurate when a broad filter is provided (such as only country). The attributes that will be looked at are:

• state - as a province code or full province name. It'll be more accurate with the code for North America.
• zip - can be any string
• country - as a 2-letter ISO country code
• city - This can be any string

All fields are case insensitive.

If your class's attributes are different than "zip", "state", etc you can map them using the "using" config in your detects_timezone call like this:

class Contact < ActiveRecord::Base
    detects_timezone using: { :province => :state, :postal_code => :zip, :country => :country, :city => :city }
end
contact = Contact.new(postal_code: 78729, province: "US")
contact.save!
puts contact.timezone
# OUTPUT: "America/Chicago"

After checking out the repo, run bin/setup to install dependencies. 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/jayelkaake/user_timezone. 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.

Since this gem actually hits a free service that links timezones to locations, I've set a rate limit of 60 requests per minute.

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