The timing is correct, because the execution is set for 6:00 pm. The test dummy was dropped at 6:00 am and Linden visits Seward at 7:10 am.
At the beginning of the episode when Linden visits Seward at the prison he states it is 11 hours before his execution. That would mean it should be around 1pm. The clock behind Linden shows 7:10. This time is also shown again on a different clock after she leaves to make a call.
At the beginning of the episode when Linden visits Seward at the prison he states it is 11 hours before his execution. That would mean it should be around 1pm. The clock behind Linden shows 2:35.