First idea: http://pastebin.com/mutmaaym

Period 1: 7:35-8:21                           Block 1/2: 7:35-9:13
Period 2: 8:26-9:14
Period 3: 9:19-10:05                          Block 3/4: 9:18-10:56
Period 4: 10:10-10:56
LUNCH: 11:01-11:36                            LUNCH: 11:01-11:34
Period 5: 11:41-12:27
Period 6: 12:32-1:18                          Block 5/6: 11:39-1:17
Period 7: 1:23-2:09
Period 8: 2:14-3:00                           Block 7/8: 1:22-3:00

46 minute periods; 45 minute lunch            98 minute periods; 43 minute lunch