Check your PC for viruses and so caled "jokes".
About up to an hour at max
I finally figured this one out. You've got to use the point of a pen, and then push repeatedly on the function you want to set. After repeatedly pushing the time set button with the point of a pen, I finally got the hour display to flash. With the hour flashing, I repeatedly pushed the down arrow button with the point of a pen. After many pushes, I managed to get the hour to decrease by an hour. I then had to repeatedly push (with the point of a pen) the time set button for it to cycle through the various functions to return it to normal operation. Good luck with this one. It really is a pain to set.
It takes light exactly one hour to travel in 1 hour.
Exactly 15 km per hour.
Depends on the time of year and place. When you are at the equator, the days are exactly 12 hours and the nights are exactly 12 hours.
At every hour exactly, for example 'the train will leave at 1pm or 2pm and so on - on the hour.
Exactly 1 hour
No.
There are exactly 144,000 seconds in a 40 hour work week. There are 2,400 minutes in 40 hours and 144,000 second in 2,400 minutes.
Cleaning a car.
Exactly 100 miles
one hour