Half Over the Prime Meridian

In an alternate timeline of our world, the world stopped.
In January of 1956, people all over the world went to sleep, but when they woke up, the night hadn't ended. It was dark. All of Europe, Asia, Africa, and Australia was covered in darkness, and the Americas in endless light. News publications all across the globe were filled with headlines talking about this phenomenon. Until one day, they went silent.
April 1958, the governments of the Americas were awaiting to be telephoned by the rest of the world, but as the days passed one by one, they heard nothing. After two months, they assumed that the rest of the world was no longer with them.