feat: Add TIME_ZONE environment variable

Author: sman591

app.json

@@ -69,6 +69,10 @@
     "HM_DOMAIN_NAME": {
       "description": "Domain name hosting the website (e.g. apply.example.com)",
       "required": true
+    },
+    "TIME_ZONE": {
+      "description": "Time zone (e.g. America/New_York, default is UTC)",
+      "required": false
     }
   },
   "addons": [

app/views/manage/configs/index.html.haml

@@ -68,6 +68,8 @@
         %hr
         = render 'config_row', name: 'Rollbar Access Token', key: 'ROLLBAR_ACCESS_TOKEN', secret: true, required: false
         %hr
+        = render 'config_row', name: 'Time Zone', key: 'TIME_ZONE', default: 'UTC', required: false
+        %hr
         %p.mb-0
           %b Email Provider
         - if Rails.application.config.action_mailer.delivery_method == :smtp

config/application.rb

@@ -18,6 +18,10 @@ class Application < Rails::Application
     # -- all .rb files in that directory are automatically loaded after loading
     # the framework and any gems in your application.
 
+    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
+    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
+    config.time_zone = ENV["TIME_ZONE"].presence || "UTC"
+
     config.active_job.queue_adapter = :sidekiq
   end
 end

docs/deployment-environment-variables.md

@@ -20,6 +20,7 @@ AWS_REGION="us-east-1"
 ROLLBAR_ACCESS_TOKEN="<server-side rollbar token>"
 SPARKPOST_API_KEY="<sparkpost api key>"
 SPARKPOST_CAMPAIGN_ID="my-hackathon"
+TIME_ZONE="America/New_York"
 ```
 
 _Also see [app.json](https://github.com/codeRIT/hackathon_manager/blob/master/app.json)_
@@ -113,6 +114,18 @@ MLH_KEY=""
 MLH_SECRET=""
 ```
 
+### Time Zone
+
+By default, charts & timestamps will be in UTC.
+
+>HackathonManager will crash at startup if the time zone isn't valid.
+>
+>To find your appropriate time zone (e.g. `America/New_York`), see "TZ database name" on [Wikipedia](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones)
+
+```bash
+TIME_ZONE="America/Los_Angeles"
+```
+
 ### Skylight
 
 Skylight provides detailed performance analytics for the app, if you chose to use it.