from = Time.parse("2013-04-05 15:00")to = Time.now
total_seconds = (from-to)
days = (total_seconds/ 86400).to_i
hours = ((total_seconds/ 3600) % 24).to_i
minutes = ((total_seconds % 3600) / 60).to_i
seconds = ((total_seconds % 3600) % 60).to_i
puts "#{days} day#{"s" if days > 1} #{hours}:#{minutes}:#{seconds}"