You must be knowing that there are 24 time zones in the world, 15 degrees apart from each other. It means new year will be entering these time zones of different time given to respective location. To understand this, you first need to know about “International Date Line”. It separates two consecutive calendar dates. It is shown by the green line on following Google Map screen grab. Once this line is crossed you are into a new calendar date.
The place which celebrates the new year first is in that red circle. Let’s zoom in that part. Place showed by the red pin is the place where new year will enter first. This place is known as “Line Islands (Kiribati, Caroline Island)” having -9.913194, -150.204695 coordinates. But this is the inhabited place, it is designated as a wildlife sanctuary. It means people who will celebrate the new year 2018 first will from Tarawa atoll from the Republic of Kiribati. This country has a population just above 100,000.
Same, one can ask which country or place will celebrate new year last? Baker Island will see the new year at last, but again it is an inhabited island. That means people of Hawaii will celebrate the new year 2018 after the whole world. And finally, that makes the USA the last country to welcome the new year 2018.