Bell Timings with zero period

Period Timings
Assembly 07:20 – 07:40 am
Zero 07:40 – 08:20 am
1st 08:20 – 08:55 am
2nd 08:55 – 09:30 am
3rd 09:30 – 10:05 am
Recess 10:05 – 10:25 am
4th 10:25 – 11:05 am
5th 11:05 – 11:40 am
6th 11:40 – 12:20 pm
7th 12:20 – 1:00 pm
8th 1:00 – 1:40 pm