No.  The daylight changes gradually increasing or decreasing five to seven minutes per day.  The shortest day of the year is December 21 and that is the darkest day.  On the northern coast of Alaska there are a few months when the sun doesn't rise, but it's not six months.  The length of the total darkness depends on how far north the town or village is.  Fairbanks and Anchorage never have total darkness even on the shortest day of the year.