How do I know if my clinical diagnoses of depression/anxiety means I have a right to accommodations from prospective employer?

I have a clinical diagnosis of depression/anxiety, which I have dealt with for 20+ years. I have nonetheless been successful in academics (graduated college with 4.0) & work. A key to this is that I have been able to have jobs with flexible schedules, i.e., where I don't work set hours or work less than full time. This flexibility helps me work when my brain is feeling well and take a break when it is not. These flexible-schedule jobs have come about in an organic way – been offered to me, or advertised as flexible hours – but I am now applying to jobs that don't advertise as such. How do I know if I have a right to reasonable schedule accommodations because of this diagnosis? How do I determine what "reasonable" means? How do I assert this right/what do I say to potential employers?