I can and have done so for a period of 7 years. The problem is that developers want to work for fancy big box companies with big salaries and it's exactly those

I can and have done so for a period of 7 years. The problem is that developers want to work for fancy big box companies with big salaries and it's exactly those type of companies that aren't going to allow you to do this. You have to find a small to medium sized business if you want flexible hours. If you do get an interview with such a business make sure it's clear as part of your contract you only plan on working 32 hours a week. After a while they may try to cajole you into working more hours and you will need to stand your ground.