The three takeoffs and landings that are required to act as pilot in command at night must be done during the time period

1 hour after sunset to 1 hour before sunrise.

Explanation:

The three departures and arrivals that are required to go about as pilot in direction around evening time must be finished during the timeframe from 1 hour after nightfall to 1 hour before dawn.

To go about as pilot in order of an airplane conveying travelers, the pilot probably made three departures and three arrivals inside the previous 90 days in an airplane of a similar classification, class, and type, if a sort rating is required

the answer to your question would be something called hertz. the unit of measurement called a hertz, which is one cycle per second, is used to measure clock speed. within one cycle, your computer processes, refreshes, or updates itself to the changes that it is going through. in the case of computer clock speed, one hertz equals one tick per second. the clock speed of computers is usually measured in megahertz (mhz) or gigahertz (ghz)