diff --git a/app/helpers/time_zone_helper.rb b/app/helpers/time_zone_helper.rb
index daf99ad9b5e..00f65b72c8e 100644
--- a/app/helpers/time_zone_helper.rb
+++ b/app/helpers/time_zone_helper.rb
@@ -1,7 +1,26 @@
 # frozen_string_literal: true
 
 module TimeZoneHelper
-  def timezone_data
+  TIME_ZONE_FORMAT_ATTRS = {
+    short: %i[identifier name offset],
+    full: %i[identifier name abbr offset formatted_offset]
+  }.freeze
+  private_constant :TIME_ZONE_FORMAT_ATTRS
+
+  # format:
+  #   * :full - all available fields
+  #   * :short (default)
+  #
+  # Example:
+  #   timezone_data # :short by default
+  #   timezone_data(format: :full)
+  #
+  def timezone_data(format: :short)
+    attrs = TIME_ZONE_FORMAT_ATTRS.fetch(format) do
+      valid_formats = TIME_ZONE_FORMAT_ATTRS.keys.map { |k| ":#{k}"}.join(", ")
+      raise ArgumentError.new("Invalid format :#{format}. Valid formats are #{valid_formats}.")
+    end
+
     ActiveSupport::TimeZone.all.map do |timezone|
       {
         identifier: timezone.tzinfo.identifier,
@@ -9,7 +28,7 @@ module TimeZoneHelper
         abbr: timezone.tzinfo.strftime('%Z'),
         offset: timezone.now.utc_offset,
         formatted_offset: timezone.now.formatted_offset
-      }
+      }.slice(*attrs)
     end
   end
 end
diff --git a/spec/helpers/time_zone_helper_spec.rb b/spec/helpers/time_zone_helper_spec.rb
index 7e7eb368474..391e9bd38ed 100644
--- a/spec/helpers/time_zone_helper_spec.rb
+++ b/spec/helpers/time_zone_helper_spec.rb
@@ -4,32 +4,68 @@ require 'spec_helper'
 
 RSpec.describe TimeZoneHelper, :aggregate_failures do
   describe '#timezone_data' do
-    subject(:timezone_data) { helper.timezone_data }
+    context 'with short format' do
+      subject(:timezone_data) { helper.timezone_data }
 
-    it 'matches schema' do
-      expect(timezone_data).not_to be_empty
+      it 'matches schema' do
+        expect(timezone_data).not_to be_empty
 
-      timezone_data.each_with_index do |timezone_hash, i|
-        expect(timezone_hash.keys).to contain_exactly(
-          :identifier,
-          :name,
-          :abbr,
-          :offset,
-          :formatted_offset
-        ), "Failed at index #{i}"
+        timezone_data.each_with_index do |timezone_hash, i|
+          expect(timezone_hash.keys).to contain_exactly(
+            :identifier,
+            :name,
+            :offset
+          ), "Failed at index #{i}"
+        end
+      end
+
+      it 'formats for display' do
+        tz = ActiveSupport::TimeZone.all[0]
+
+        expect(timezone_data[0]).to eq(
+          identifier: tz.tzinfo.identifier,
+          name: tz.name,
+          offset: tz.now.utc_offset
+        )
       end
     end
 
-    it 'formats for display' do
-      tz = ActiveSupport::TimeZone.all[0]
+    context 'with full format' do
+      subject(:timezone_data) { helper.timezone_data(format: :full) }
 
-      expect(timezone_data[0]).to eq(
-        identifier: tz.tzinfo.identifier,
-        name: tz.name,
-        abbr: tz.tzinfo.strftime('%Z'),
-        offset: tz.now.utc_offset,
-        formatted_offset: tz.now.formatted_offset
-      )
+      it 'matches schema' do
+        expect(timezone_data).not_to be_empty
+
+        timezone_data.each_with_index do |timezone_hash, i|
+          expect(timezone_hash.keys).to contain_exactly(
+            :identifier,
+            :name,
+            :abbr,
+            :offset,
+            :formatted_offset
+          ), "Failed at index #{i}"
+        end
+      end
+
+      it 'formats for display' do
+        tz = ActiveSupport::TimeZone.all[0]
+
+        expect(timezone_data[0]).to eq(
+          identifier: tz.tzinfo.identifier,
+          name: tz.name,
+          abbr: tz.tzinfo.strftime('%Z'),
+          offset: tz.now.utc_offset,
+          formatted_offset: tz.now.formatted_offset
+        )
+      end
+    end
+
+    context 'with unknown format' do
+      subject(:timezone_data) { helper.timezone_data(format: :unknown) }
+
+      it 'raises an exception' do
+        expect { timezone_data }.to raise_error ArgumentError, 'Invalid format :unknown. Valid formats are :short, :full.'
+      end
     end
   end
 end