See the following repo for example project: https://github.com/aarona/date_picker
At first I thought the problem was caused by the model being tableless but when associating it with the database through a migration I still get an error:
wrong number of arguments (1 for 0)
on this line:
<%= f.datepicker :start_date,  :class => 'short' %>
I get an error about delete method not found if the model is tableless.