The jet stream in the winter is a lot stronger than it is during the summer. The airlines adjust the times based on the wind for that time of the year. During the winter, going to Hawaii, planes will sometimes see headwinds that average 125 kts, and during the summer the wind average might be 20 kts.
The good news is that your trip home should be a lot faster. However, there are days when you fly to Hawaii and face a brutal headwind one day, and the very next day you look forward to those great winds and they are only 50 kts.
In Japan, the jet stream is sometimes over 200 kts. Good thing most flights go north and south in Japan. I bring that up because I just got back. Looks like I will be leaving Hawaii in September to live in Japan for three years and work for a small company that has 737s. Anyway....
T R could be right about the daylight savings time, two hours is a big difference. One hour or 1.5 hours time difference is all it should be based on the winds. Also, everyone above is correct about flying slower these days to save fuel and that 737s fly slower. So, Alaska will take a little longer and they might not be able to make it if the winds are really bad.
Aloha flights had to fly Vancouver to Oakland to Honolulu about one day each month during the winter because the winds were so bad and that only happened a few times each year. It actually only took a couple hours longer that way and didn't hurt the schedule too much. However, most passengers did not like the side trip.