Several Questions come to mind...
First: How is the clock powered? If it is by batteries would not the batteries run down when they went through time 30 years into the past?
Second: IF the clock/chronometer actually did record the passage of time, backwards would it not also record the passage of time forwards when it re-entered our time-stream and thus return to us showing the correct time in the present?
Third were there any Moose spotted in the area of the time displacement? How about cheese?
Because in 1964 you switched the balloon clock back 30 years in order to make the 2034 people that us 2004 people had caused that little 1934 accident. Duh!
I already explained this to you, don't you remember? Wait...what year is this again?