0800-0850 1st period
0900-0950 2nd period
0950-1010 cleaning time in the morning
1010-1100 3rd period
1110-1200 4th period
1200-1310 lunch break
1310-1400 5th period
1410-1500 6th period
1510-1600 7th period
1610-1700 8th period (if necessary)