Mornings are usually the best times, but sometimes you encounter people who misunderstands library versus living room. Had a guy once who was sleeping and snooring loudy. Sometimes you also have groups of gypsies, romani people, in the morning who uses it as a living room with music and loud conversations. After school ends it turns into an informal youth club combined with a caffe atmosphere. There is a securitas guard in the evening and library staff during the day, but most of the time they let anarchy rule. Also avoid the "library" during events especially with children. Children are fantastic but not in a small "library". If you decide to use the library avoid any window seating outside of official opening hours, since people who have forgotten their library card bangs loudly on the window to get in.