We do not know the day or the hour. We are commanded to know the season. As Christ wept over Jerusalem on of the reasons He listed for her destruction was she did not know the time of her visitation.
We can't; unless GOD uses GMT!
There are more than 24 times zones across the earth as well as two differing days at any one instance.
It's 8:03am 7-24 as I post this.
Mark; what time and date is it where you are at??