Question

how people who go to the poles decide what time to use

Answer 1

Answer:

when sun rise in the poles

Answer 2

Answer:

To set their time zones, most countries simply offset time in hour increments, according to their distance from Greenwich; for example, Eastern Daylight Time (EDT) in the U.S. is expressed in universal time as UTC-4. Some places, however, including India, Iran, Afghanistan and parts of Australia, use a half-hour offset; so, for example, the Canadian province of Newfoundland has as its standard time UTC-3:30.