Create TimeHelper module

app/helpers/time_helper.rb

@@ -0,0 +1,12 @@
+module TimeHelper
+
+  # convert timestamps ('12:34:56.789') to seconds
+  def time_to_f(timestamp)
+    unless timestamp.nil?
+      timestamp = timestamp.split(':')
+      return timestamp[0].to_i * 60 * 60 + timestamp[1].to_i * 60 + timestamp[2].to_f
+    end
+    nil
+  end
+
+end