This class parse a hash of params looking for a date field and parse its value to timestamp

Parser.rb

  class Parser
    def initialize(hash)
      @hash = hash
    end

    def parse()
      @hash.inject({}) do |h, (k, v)|
        h[k] = parse_element(k, v)
        h
      end
    end

    private

    def parse_element(parent, element)
      case element
        when Array
         element.map{|x| parse_element(parent, x)}
        when Hash
          element.inject({}) do |h, (k, v)|
            h[k] = parse_element(k, v)
            h
          end
        else
          parent.match(/(_at$|^timestamp$|^datetime$|date$)/) ? parse_time(element) : element
        end
    end

    def parse_time(element)
      DateTime.strptime(element, '%m/%d/%Y').to_i if element.present?
    end

  end

Parser.new(hash).parse()