db/migrate/20150515140017_convert_stop_times_to_intervals.rb
class ConvertStopTimesToIntervals < ActiveRecord::Migration
def change
remove_column :stop_times, :arrival_time
remove_column :stop_times, :departure_time
add_column :stop_times, :arrival_time, :interval
add_column :stop_times, :departure_time, :interval
end
end