module Rufus

def self.parse_time_string(string)


or responds to #to_s will be OK.
Note will call #to_s on the input "string", so anything that is a String

Rufus.parse_time_string "1w2d" # => 777600.0
Rufus.parse_time_string "1h10s" # => 3610.0
Rufus.parse_time_string "1h" # => 3600.0
Rufus.parse_time_string "1000" # => 1.0
Rufus.parse_time_string "500" # => 0.5
Rufus.parse_time_string "0.5" # => 0.5

Some examples :

'nada' -> millisecond
y -> year
M -> month
s -> second
m -> minute
h -> hour
d -> day
w -> week

(millisecond count).
turns a time duration expressed as a string into a Float instance
Turns a string like '1m10s' into a float like '70.0', more formally, 
def self.parse_time_string(string)
  string = string.to_s
  return 0.0 if string == ''
  m = string.match(/^(-?)([\d\.#{DURATION_LETTERS}]+)$/)
  raise ArgumentError.new("cannot parse '#{string}'") unless m
  mod = m[1] == '-' ? -1.0 : 1.0
  val = 0.0
  s = m[2]
  while s.length > 0
    m = nil
    if m = s.match(/^(\d+|\d+\.\d*|\d*\.\d+)([#{DURATION_LETTERS}])(.*)$/)
      val += m[1].to_f * DURATIONS[m[2]]
    elsif s.match(/^\d+$/)
      val += s.to_i / 1000.0
    elsif s.match(/^\d*\.\d*$/)
      val += s.to_f
    else
      raise ArgumentError.new("cannot parse '#{string}' (especially '#{s}')")
    end
    break unless m && m[3]
    s = m[3]
  end
  mod * val
end