The temperature is in red.
The curve rises when the temperature decreases.
The pendulum position is in blue.
The data time axis is UTC time.
To map it to local time, the local UTC offset must be subtracted.
For example Summit, NJ is UTC + 4 (summer) or UTC + 5 (winter),
so plots begin at 4 or 5 am, and extend into the next day's 4 or 5 am.