Deke/Near's Time Script, Tone Changing

[OS]

Hello, all. I would just like to know if anyone knows how to get the Tone Change Effect that Deke/Near got with this method:

def get_tone
  hour=get_hour.floor
  minutes=get_minute + hour*@hour_length
  phase_shift=Math::PI*(minutes/(@hour_length*@day_length))
  illumination=  -150+ 165*Math.sin(phase_shift)
  tone=Tone.new(illumination,illumination,illumination,0)
  return tone
end

without calling the methods in their script. I need this for my own time script that is a little different. It uses a variable for each value instead of a method. I just need to know how to use this formula, only with things changed to use these variables:

@minutes #Minutes in an hour
@hours #Hours in a day
@seconds #Seconds in a minute
@minute #the current minute
@hour #the current hour
@second #the current second
@frames #the frames per second
@frame #the current frame

If anyone can help, I thank you greatly. I will keep working on it for now. Peace!