Well, considering they first started digging in the Valley of the Kings in 1917 (in search of King Tutankhamuns tomb) and actually found King Tutankhamun's tomb (or at least the steps leading into it) on November 4, 1922, I guess you could say it took them around 5 years (they being Howard Carter and his crew).
You can find a timeline here which may be of use to you.
You can find a timeline here which may be of use to you.
