When a person is certified for intensive treatment pursuant to Sections 5250 and 5270.15, a certification review hearing shall be held unless judicial review has been requested as provided in Sections 5275 and 5276. The certification review hearing shall be within four days of the date on which the person is certified for a period of intensive treatment unless postponed by request of the person or his or her attorney or advocate. Hearings may be postponed for 48 hours or, in counties with a population of 100,000 or less, until the next regularly scheduled hearing date.