Getting her fourth grade son to and from school has been a carefully scheduled routine for Tamara Garcia. The single mother drops off her son at Booker Elementary School at 7:30 a.m. — 10 minutes before classes begin at 7:40 a.m. — giving her time to clock in to her 8 a.m. job. Her son waits at an after-school program until her shift ends so she can pick him up. When Booker Elementary leaders announced that classes would begin at 9:15 a.m. next school year, Garcia’s balanced routine looked as if it would be turned upside down. That’s why she and hundreds of other Booker parents signed a petition opposing the 1-hour-35-minute change. “I really just don’t have any help with pickups and drop-offs,” Garcia said.…