Using created_at instead of legacy 'uploaddatetime' field

app/models/screenshot.rb

@@ -2,7 +2,7 @@ class Screenshot < ActiveRecord::Base
   belongs_to :package, :inverse_of=>:screenshots
 
   default_scope {
-    order('uploaddatetime DESC')
+    order('created_at DESC')
   }
 
   has_attached_file :image,
@@ -29,7 +29,11 @@ class Screenshot < ActiveRecord::Base
 
   # Calculate how many days ago this screenshot has been uploaded
   def age_days
-    seconds = Time.now-self.uploaddatetime
+    if self.created_at
+      seconds = Time.now - self.created_at
+    else
+      seconds = 0
+    end
     days = (seconds/86400).to_i
     days ? "#{days} days ago" : 'today'
   end

app/views/packages/details.slim

@@ -25,7 +25,7 @@
                   ] Delete screenshot
 
                 p Uploader IP=#{screenshot.uploaderip}
-                p Uploaded #{screenshot.age_days} (#{screenshot.uploaddatetime})
+                p Uploaded #{screenshot.age_days} (#{screenshot.created_at})
                 p Status: #{screenshot.status}
 
     - else