Resolving the Error

To resolve this error, you'll need to make sure that the tzinfo-data gem is being included in your Gemfile.

First of all, check your Gemfile to see if there is an existing reference to tzinfo-data. If there isn't already a reference, then add the following line:

gem 'tzinfo-data'

You may find that there is already a line like the following:

gem 'tzinfo-data', platforms: [:mingw, :mswin]

If you are using a 64-bit version of Ruby on Windows, then add :x64_mingw to the list of platforms as follows:

gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw]

Alternatively, you can remove the platforms option altogether.

After doing this, run bundle update at the command line to install the tzinfo-data gem and you'll then be able to start your Rails server or console.


The TZInfo::DataSourceNotFound error is being raised by TZInfo, a dependency of the Active Support component of Rails. TZInfo is looking for a source of time zone data on your system, but failing to find one.

On many Unix-based systems (e.g. Linux), TZInfo is able to use the system zoneinfo directory as a source of data. However, Windows doesn't include such a

directory, so the tzinfo-data gem needs to be installed instead. The tzinfo-data gem contains the same zoneinfo data, packaged as a set of Ruby modules.

Rails generates a default Gemfile when the application is first created. If the application is created on Windows, then a dependency for tzinfo-data will be included. However (as of Rails version 4.1.0), this omits :x64_mingw from the list of platforms, so doesn't work correctly on 64-bit Windows versions of Ruby. This should be fixed in future Rails releases.

add this to your Gemfile and bundle install.

gem 'tzinfo'