I thought it meant "If you are in England which are the most westerly and most easterly States of America?"
Is the date line the same as the 0 degrees east or west?
Living here in Greenwich in the eastern Hemisphere we are .09 of a second (just under a mile) from the 0 degree line.
There are 360 degrees in a circle (as the ancient Sumerians thought there were 360 days in a year, not 365.26)
Therefore the date line is 12 hours/180 degrees from Greenwich in either direction.
Very conveniently this happens to be the Baring Strait between Alaska and Russia
Therefore from a geographical (not political) point of view the Political state of Alaska is in both eastern and western hemispheres
There is a fascinating short book called Longitude by Deva Sobell it explains all this in simple English and it make a great story of double dealing and intrigue.