class Rufus::Scheduler

def self.parse_duration(string, opts={})


Rufus::Scheduler.parse_duration "-1h" # => -3600.0
Rufus::Scheduler.parse_duration "-0.5" # => -0.5

Negative time strings are OK (Thanks Danny Fullerton):

Rufus::Scheduler.parse_duration "1w2d" # => 777600.0
Rufus::Scheduler.parse_duration "1h10s" # => 3610.0
Rufus::Scheduler.parse_duration "1h" # => 3600.0
Rufus::Scheduler.parse_duration "1000" # => 1.0
Rufus::Scheduler.parse_duration "500" # => 0.5
Rufus::Scheduler.parse_duration "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_duration(string, opts={})
  string = string.to_s
  return 0.0 if string == ''
  m = string.match(/^(-?)([\d\.#{DURATION_LETTERS}]+)$/)
  return nil if m.nil? && opts[:no_error]
  raise ArgumentError.new("cannot parse '#{string}'") if m.nil?
  mod = m[1] == '-' ? -1.0 : 1.0
  val = 0.0
  s = m[2]
  while s.length > 0
    m = nil
    if m = s.match(/^(\d+|\d+\.\d*|\d*\.\d+)([#{DURATION_LETTERS}])(.*)$/)
      val += m[1].to_f * DURATIONS[m[2]]
    elsif s.match(/^\d+$/)
      val += s.to_i
    elsif s.match(/^\d*\.\d*$/)
      val += s.to_f
    elsif opts[:no_error]
      return nil
    else
      raise ArgumentError.new(
        "cannot parse '#{string}' (especially '#{s}')"
      )
    end
    break unless m && m[3]
    s = m[3]
  end
  mod * val
end