[thorin]

It's a lot easier to go part time in a job you already have than find a new part time job. If you are already successful in your job start by asking to move to having every Friday off or even every second Friday. This is very popular in UK/Europe. If this is working maybe you can drop another day after some time.

Alternatively a lot of companies let you take as much unpaid leave as you want (as long as you don't miss anything critical). This amounts to the same thing but gives you a lot of flexibility.