refactor lifetime_select helper

app/helpers/snippets_helper.rb

 module SnippetsHelper
-  def snippet_lifetime_select_options
+  def lifetime_select_options
     options = [
         ['forever', nil],
-        ['1 day',   Date.strptime("#{Date.current.day}.#{Date.current.month}.#{Date.current.year}", "%d.%m.%Y") + 1.day],
-        ['1 week',  Date.strptime("#{Date.current.day}.#{Date.current.month}.#{Date.current.year}", "%d.%m.%Y") + 1.week],
-        ['1 month', Date.strptime("#{Date.current.day}.#{Date.current.month}.#{Date.current.year}", "%d.%m.%Y") + 1.month]
+        ['1 day',   "#{Date.current + 1.day}"],
+        ['1 week',  "#{Date.current + 1.week}"],
+        ['1 month', "#{Date.current + 1.month}"]
     ]
     options_for_select(options)
   end

app/views/snippets/_form.html.haml

@@ -14,7 +14,7 @@
         %td= f.text_field :file_name, :placeholder => "example.rb"
       %tr
         %td= f.label "Lifetime"
-        %td= f.select :expires_at, snippet_lifetime_select_options
+        %td= f.select :expires_at, lifetime_select_options
       %tr
         %td{:colspan => 2}
           = f.label :content, "Code"