在控制器中使用日期数据的简便方法？

Question

处理从datetime_select帮助程序提交的日期时间值，以便将其与现有已保存的数据进行比较。

我使用以下代码，但感觉有点麻烦。

DateTime.parse("#{params['start_date(1i)'].to_i}-#{params['start_date(2i)'].to_i}-#{params['start_date(3i)'].to_i} #{params['start_date(4i)'].to_i}:#{params['start_date(5i)'].to_i} -500")

是否有更简单的方法来构建日期时间对象？

编辑：

这是我的表单代码：

= form_for(@charity) do |f|
  - if @charity.errors.any?
    #error_explanation
      %h2
        = pluralize(@charity.errors.count, "error")
        prohibited this charity from being saved:
      %ul
        - @charity.errors.full_messages.each do |msg|
          %li= msg
  .field
    = f.label :name, 'Name *'
    = f.text_field :name

  %fieldset
    %legend Dates in Eastern Standard Time
    .field
      = f.label :start_date, 'Start Date *'
      = f.datetime_select :start_date, :default => DateTime.now
    .field
      = f.label :end_date, 'End Date *'
      = f.datetime_select :end_date, :default => DateTime.now
    .field
      = f.label :percentage, 'Percentage of sales to be donated *'
      = f.text_field :percentage
    .field
      = f.label :charity_number, 'The identification number for your charity *'
      = f.text_field :charity_number
    .field
      Donation options: 
      %span{ title: "Dollar amounts that you wish to allow people to donate on top of their order.", class: "tooltip_hover" }= image_tag "question.png"
      - DonationOption.all.each do |option|
        = f.label option.id, number_to_currency(option.amount, unit: "$"), class: "donation_label"
        = check_box_tag "charity[donation_option_ids][]", option.id, @charity.donation_option_ids.include?(option.id), class: "donation_check"
      .actions
        = f.submit nil, class: "btn-primary"

控制器：

def update
  @charity = Charity.find(params[:id])
  respond_to do |format|
    if @charity.update_values(params[:charity])
      format.html { redirect_to @charity, notice: 'Charity was successfully updated.', :charity => @charity }
      format.json { head :ok }
    else
      format.html { render action: "edit" }
      format.json { render json: @charity.errors, status: :unprocessable_entity }
    end
  end
end

update_values方法：

def update_values(attributes)
  s_date = DateTime.parse("#{attributes['start_date(1i)'].to_i}-#{attributes['start_date(2i)'].to_i}-#{attributes['start_date(3i)'].to_i} #{attributes['start_date(4i)'].to_i}:#{attributes['start_date(5i)'].to_i} -500")
  attributes.delete('start_date(1i)')
  attributes.delete('start_date(2i)')
  attributes.delete('start_date(3i)')
  attributes.delete('start_date(4i)')
  attributes.delete('start_date(5i)')
  # if the charity has not started yet
  if DateTime.now.utc < self.start_date.utc
    self.start_date = s_date
    attributes.merge!(reset_create_job)
  end

  e_date = DateTime.parse("#{attributes['end_date(1i)'].to_i}-#{attributes['end_date(2i)'].to_i}-#{attributes['end_date(3i)'].to_i} #{attributes['end_date(4i)'].to_i}:#{attributes['end_date(5i)'].to_i} -500")
  attributes.delete('end_date(1i)')
  attributes.delete('end_date(2i)')
  attributes.delete('end_date(3i)')
  attributes.delete('end_date(4i)')
  attributes.delete('end_date(5i)')
  if DateTime.now.utc < self.end_date.utc
    self.end_date = e_date
    attributes.merge!(reset_delete_job)
  end

  self.update_attributes(attributes)
end