In Oslo, sun rise and sun set time for late October are 8-18 for the first 3 weeks, then 7-17 the last week (we change to Winter time 25th October). This is a time of the year when day length shorten very quickly, we lose 5 minutes every day.
In Tromsų, you are looking at 8-15 the last week, 8:30-16 the first three weeks. They lose 9 minutes of day time every day.
More night time means more chances to see Northern Lights.