Take a look at my example again - there are 30 consecutive hours off at the beginning. After the pilot had worked his 7 days, he had 137 hours without a 30 hour rest. But, that's ok because he DID have 30+ consecutive hours of rest in the previous 168. 168 - 137 = 31. In a 168 hour look back upon his release on day 7, he had 31 consecutive hours of rest - at the beginning. In other words, you can go 138 hours before needing a 30 break in duty.