No. Generally, all nonexempt employees in the defined work unit must follow the adopted alternative workweek schedule.
Alternative workweeks are not intended to allow employees to switch between schedules, and a traditional eight-hour day cannot be an option during the adoption process (Labor Code Section 500(c); DLSE Manual 56.7.2.2).
Employees may work a traditional schedule only if they are unable to work the alternative schedule and require accommodation (e.g., for protected reasons like medical or religious needs).
Read about Alternative Workweek Scheduling in the HR Library.