Change plural form of generated model in rails?

I'm using this command:

rails generate model DayOfMonth day:integer

Rails generated the model "DayOfMonth" and the table "day_of_months".

I want it to create the table "days_of_month" instead.

I know this has something to do with the Inflector class and the inflector.rb in initializers folder.

But I don't understand how to get this to work.

I'm using Rails 3.

Could someone help me out here or point me to a tutorial for this?

Thanks