Days start getting shorter in the northern hemisphere after summer solstice in June, and they stop getting shorter on the winter solstice, 21.st of December when they resume getting longer.
In Grímsey island by the Arctic Circle, Iceland's northernmost part, the changes are quite extreme from 24 hours daylight during summer to only few hours daylight during the peak of winter. This beautiful photo was taken by a local fisherman this morning on the way to the fishing grounds. The island can be seen in the horizon.
Sunrise in Grímsey is currently around 8 in the morning and sunset around 17.00 in the afternoon.