hobby ECs?

how would you put down self-directed hobbies on the common app, under activities? a couple hours a week 52 weeks a year?

I would not include them.

uh why not

I actually WOULD include them. My D17 got into her ED school of around 15% acceptance rate, so there were lots of applicants with similar GPA/scores as her, and one thing that helped her stand out from that crowd was her ECs, which included self-directed ones, her in-school ones had no leadership in them either.