Under current law, you may take a 34hr break at any time. There is discussion of changing it so that you can only take a 34 once per week (rough verbage) and that it must encompass two periods of time, but I'm not very familiar with the upcoming change. I use elogs, so the 'puter handles it for me.
The new reset must include 2 periods of 1-5AM, and you may use it once per week.
The old reset (they way it is for a couple more months?) is 34 hours off resets the clock, that's it. Use it as you wish.
The recap is simple, if you fill it out, do the math. 70-(minus)hours used for today(first day)=hours available tomorrow. Do that for 7 days. On the 8th day, you get the first days hours back, and it keeps rolling forward the same way.
After your 34hr reset, you get your 70hrs back.. So if you worked 45 hrs then have a day off with 34 consecutive hrs then you get back to 70hrs available. Any time you have 34 consecutive hours off duty, your hours reset to 70 hrs. Until July 1st of this year when you can only reset hours once a week regardless if you have to different periods of 34hrs off duty.. And you need two days off in a row consisting of two consecutive 1am-5am periods off. So if you get out Saturday morning at 2am, you have to have Sunday off and that's your first 1-5am period off then Monday 1-5am off and then can come back to work at 5:01am and that's a 51hrs reset.