Here's how to calculate the number of nanoseconds in one hour:

* Seconds in an hour: 1 hour = 60 minutes * 60 seconds/minute = 3600 seconds

* Nanoseconds in a second: 1 second = 1,000,000,000 nanoseconds (1 billion)

Therefore:

1 hour * 3600 seconds/hour * 1,000,000,000 nanoseconds/second = 3,600,000,000,000 nanoseconds