because we sleep at night and are active during the day, and so we need to track that in a way that is universal. if i mention 12:00, people understand that it is noon where i am, and if i mention 22:00, they know it’s bedtime.
the whole point of time zones is to have time cohesion in a wider region within margin of error, so people on the far east and far west of a time zone still see the sun at roughly its highest point in the sky at 12:00. you can take a train to a neighbouring city without having to worry about needing to adjust your timekeeping devices by a few minutes.
to put your scenario into perspective, china has already done what you suggested on a smaller scale: the entire country is on UTC+8. this is great for cities like beijing and hong kong
because we sleep at night and are active during the day, and so we need to track that in a way that is universal. if i mention 12:00, people understand that it is noon where i am, and if i mention 22:00, they know it’s bedtime.
the whole point of time zones is to have time cohesion in a wider region within margin of error, so people on the far east and far west of a time zone still see the sun at roughly its highest point in the sky at 12:00. you can take a train to a neighbouring city without having to worry about needing to adjust your timekeeping devices by a few minutes.
to put your scenario into perspective, china has already done what you suggested on a smaller scale: the entire country is on UTC+8. this is great for cities like beijing and hong kong