Rails date_select Madness

I love using the Rails date_select helper. It's wonderful how one simple line of code can automatically generate all you need for your users to select a month, day and year. However, I have one small annoyance with it. A user can select an invalid date (like February 30 or September 31), and Rails will automatically roll over the additional dates, instead of actually marking that field / attribute as invalid. For example, if the user selected February 31 and submitted the form, Rails would happily set the date to March 3.

Now, that really isn't an issue for alarm on my part, and in most cases I would not handle these types of mistakes (or toying around, which is most likely what I suspect if this occurs). But one of the apps I'm working on required that the user should not be able to enter these bogus dates.

The easiest way I found to do this was to do a quick check using Ruby's Date class with the selected values. The Date class raises an ArgumentError if you try to initialize it with a bogus date. I put this in my controller action where the information, including the selected date, was going to be saved:

def create
  @user = User.new(params[:user])

  selected_day = params[:user]['birthdate(1i)'].to_i
  selected_month = params[:user]['birthdate(2i)'].to_i
  selected_year = params[:user]['birthdate(3i)'].to_i
  Date.new(selected_day, selected_month, selected_year)
  
  # Other logic here, including saving the record and redirecting on
  # success, or rendering the form on failure.
rescue ArgumentError
  @user.errors.add(:birthdate, 'is an invalid date')
  # Clear the birthdate, so it doesn't show the rolled-over date in the view.
  @user.birthdate = nil
  render :action => 'new'
end

In the code above, it does all the regular Rails stuff of creating a new object with the form data. However, I added an additional statement, which is to create a new Date object. I don't use this Date object for nothing I initialize it. I simply initialize the object so that if an incorrect date is selected in the date_select helper, it will raise the ArgumentError, where I then handle the error properly. It will render the form again, displaying the standard Rails error message indicating that the birthdate is invalid.

I avoided using plugins, since I didn't have many cases where it warranted using an external library. I'm also sure I could monkey-patch this, so that all my date_select helpers worked this way, but I only had it in two places. Is there some other way of doing this? There might be. But judging by the search results I encountered while looking into this, I don't think anyone cares if the user enters bogus dates.