TzWorld

Resolve timezones from a location efficiently using PostGIS and Ecto (documentation).

TzWorld works by fetching timezone GeoJson data from this project, and then inserting it in a PostGIS table. Once populated, the database can be queried to retrieve a timezone name from coordinates.

Installation

1. Add tz_world to your list of dependencies in mix.exs:

def deps do
  [
    {:tz_world, "~> 0.1.0"}
  ]
end

After adding TzWorld as a dependency, run mix deps.get to install it.

1. Set your Ecto repository in your config.ex:

config :tz_world,
  repo: MyApp.Repo

1. If you haven't already done so, add the Geo.PostGIS Ecto extension to your project

# Create a new file anywhere in your application with the following:
Postgrex.Types.define(MyApp.PostgresTypes,
                      [Geo.PostGIS.Extension] ++ Ecto.Adapters.Postgres.extensions(),
                      json: Poison)

1. Generate the migration to create the PostGIS table that will hold the GeoJson data:

$ mix tz_world.gen.migration

Then run the migration with mix ecto.migrate.

1. Populate the table:

$ mix tz_world.install

This will Fetch GeoJson data from here, and insert it your database.

Usage

TzWorld.timezone_at(%Geo.Point{coordinates: {3.2, 45.32}})
"Europe/Paris"