irb(main):001:0> start = Time.now
=> Thu Nov 05 01:02:54 -0800 2009

irb(main):002:0> Time.now - start
=> 25.239

irb(main):003:0> (Time.now - start).duration
=> "25 seconds"

23 minutes and 35 seconds
1 hour and 33 minutes
2 days and 3 hours

class Numeric
  def duration
    secs  = self.to_int
    mins  = secs / 60
    hours = mins / 60
    days  = hours / 24

    if days > 0
      "#{days} days and #{hours % 24} hours"
    elsif hours > 0
      "#{hours} hours and #{mins % 60} minutes"
    elsif mins > 0
      "#{mins} minutes and #{secs % 60} seconds"
    elsif secs >= 0
      "#{secs} seconds"
    end
  end
end

require 'date'

start_time = Time.now
end_time = Time.now

time_diff = end_time - start_time
hours,minutes,seconds,frac = Date.day_fraction_to_time(time_diff)
puts "Time elapsed: #{hours} hours, #{minutes} minutes and #{seconds} seconds"

time_difference = current_time - old_time



 def seconds_fraction_to_time(time_difference)
    days = hours = mins = 0
      mins = (seconds / 60).to_i
      seconds = (seconds % 60 ).to_i
      hours = (mins / 60).to_i
      mins = (mins % 60).to_i
      days = (hours / 24).to_i
      hours = (hours % 24).to_i
    return [days,hours,mins,seconds]
  end

if(days > 0)
return "#{days} Days #{hours} Hours"
else
return "#{hours} Hours #{mins} Minutes"
end