In good approximation, I would say around 0 minute a week. I guess it could happen that it takes a few minutes, but I don't remember last time it happened.
yea i am really confused by all these issues people are saying they have myself..stashing merging etc...and what is crazy is we migrated large teams of programmers who's only experience with version control before git was microsoft TFS and and everyone is easily and happily chugging along. Now most of these people use gui tooling for managing git, but so what everyone gets it done with no issues or complaints with many projects big and small. we even have non-devs using it. I get jj might have some life improvements for some niche groups of people but i really have to wonder if they are the type of people who purposely make their life more complex
Forget between team members - it's an issue just for my own local dev purposes, when I'm working on multiple changes/PRs at the same time and want to test them all out before they get merged to main in the origin.