gistfile1.rb

#!/usr/bin/env ruby

require 'fileutils'

ARGV.each_with_index do |file, index|
  next unless File.exists?( file )

  filename_arr = File.basename( file ).split '_'

  # Make sure to add a couple of seconds
  new_version = Time.now.strftime( '%Y%m%d%H%M%S' ).to_i + index

  # Change the version
  filename_arr[0] = new_version
  new_name = filename_arr.join '_'

  new_file = File.join File.dirname( file ), new_name

  # Rename in filesystem
  FileUtils.mv file, new_file
end