I think I've seen one long term self-study that was ~18 months which said it worked for them. I've seen plenty of fallen off the wagon, or cautiously optimistic

I think I've seen one long term self-study that was ~18 months which said it worked for them. I've seen plenty of fallen off the wagon, or cautiously optimistic though. Maybe a mixed solution would work, biphasic sleep during the week when you're maximising productivity, monophasic when it's less important (holidays etc) to get around the constraints. Not sure, I might experiment with it.