The Doomsday Clock is a symbolic clock face, maintained since 1947 by the board of directors of the Bulletin of the Atomic Scientists at the University of Chicago. The closer the clock is to midnight, the closer the world is estimated (by the board of the Bulletin) to be to global disaster. It has no effect on us. Its setting is based on the opinion of the current people on the Board. I'm sure the people making up the Board have changed several times in the 63 years since they started using this clock face.
If you read the article on Wikipedia, you will see a chart showing where the setting has been for every year during its publication. They haven't been terribly accurate, but they aren't involved in government or politics, so they aren't any more likely to know how close we are to a nuclear war than you and I are.
People are much more skittish and excitable today than they were in the fifties and sixties. In my opinion, we are much farther away from a nuclear war than we were at that time. As I said, it is set from the opinions of a small group of people who know the science of nuclear physics, but are no more informed about world events than any other intelligent people who follow what is happening in the world. I think that the fact that it is set at 6 minutes now, instead of 16, is due to the increased pessimism of people today. I'm sure that North Korea and Iran are aware that if they started using nuclear missiles, the US and other world powers could squash them. I don't even give it a thought until someone asks about it