Timeline of a myth (Score 1)

Hi. Firstly thanks for the great show - it is always the talking point at work the day after it is shown here on Australian TV. Sometimes during the major myths, you guys seem to be running out of time - usually something to which Adam is often more stressed about. My question then is what is a typical timeline for a major myth? How would it generally take to go through the planning, build, testing and filming phases? Again thanks heaps for the great show, Alex