I usually spend 1-2 hour on Lemmy since I am not a good reader(and also non native) so it takes some time to read all the content I like on Lemmy.
I was inactive for some time because I was busy with my life but I am back and now I try to post and comment more frequently!
About 90 min according to my settings screen time. Looks like it divides into ~10 sessions throughout the day, each lasting 1-15 min.