What is the earliest/latest that a lunch can be scheduled?

I work 2pm-10pm, HR wants us to take our 30 minute lunch at
3:30-4p because the other is still in the store for coverage.

If we work 7am-3:30 can we be forced to go from 2p-2:30 and go home an
hour later?

thanks,

CA meals rules. (http://www.dir.ca.gov/dlse/FAQ_MealPeriods.htm)

"In California, an employer may not employ an employee for a work period of more than five hours per day without providing the employee with a meal period of not less than thirty minutes, except that if the total work period per day of the employee is no more than six hours, the meal period may be waived by mutual consent of both the employer and employee."

And you can see that the rule does not require the break be provided at any given time.

Not required at any specific time. Only required that you recieve it if you work more than 5 hours. And just an FYI if you are working less than 6 hours you & your employer can agree to waive the meal break.