Special variables for dates

gistfile1.rb

# == Schema Information
#
# Table name: showings
#
#  id           :integer         not null, primary key
#  start_time   :datetime
#  end_time     :datetime

class Showing < ActiveRecord::Base
  attr_accessor :showing_date, :start_date, :end_date
  
  validates :showing_date, :start_date, :end_date, :presence => true
  
  before_save :set_dates
  # used to set the instance variables for editing the form
  after_find :set_times
    
  def set_times
    self.showing_date = self.start_time.strftime("%A, %B %d, %Y") unless self.start_time.nil?
    self.start_date = self.start_time.strftime("%-I:%M%p") unless self.start_time.nil?
    self.end_date = self.end_time.strftime("%-I:%M%p") unless self.end_time.nil?
  end
    
  private

  def set_dates
    self.start_time = DateTime.strptime("#{start_date} #{showing_date} #{Time.now.zone}", "%I:%M%p %A, %B %d, %Y %z")
    self.end_time = DateTime.strptime("#{end_date} #{showing_date} #{Time.now.zone}", "%I:%M%p %A, %B %d, %Y %z")
  end

end

In the end I used a merged datetime text_field and the code here: codegram/date_validator#25 (comment)