So some airline operations person is complaining that they will have a hard time building domestic US trips based on local time, because delays might force a scheduled 30+ hours of rest to be reduced below 30 (true, but this is the case if you used 'home base' time too), and the show time of the trip could be modified into a different part of ‘Table B’ (duty period limits for an unaugmented crew), rendering the previously legal trip illegal (which is incorrect, b/c the show time of the EWR flight didn't change, only the arrival time from LAX, and thus the amount of rest in EWR going from 31 hours to 29:45). Almost a page of writing to say . . . nothing.

If you need 30+ hours of rest in EWR, either:

1. delay the EWR flight, which could make a previously legal trip illegal b/c the amount of duty is now too much with the new show time (which is time zone dependent, and thus variable based on your company choosing to use 'home base' or 'local' time rules)
2. don't delay the EWR flight, and you no longer get 30 hours of rest, so you might be illegal now b/c of that.

With option 1, if you use local time for the whole trip vs. home base time, the airline could either get lucky or unlucky. Perhaps the modification of the show time could put the pilot into a new, lower, FT or DT bracket, one that the pilot wouldn't have been in had the company used the other method, one that would make a previously legal trip illegal. Say you had a trip that had an 11:55 EST show for a 2 leg, 8:55 flight time, 13:55 duty day (08:55 PST show for the same trip). If you delay the show 15 mins to keep the 30+ hour layover, you'd now have a 12:10 EST show (09:10 PST). With EST, this takes you into a max 13 hour duty day, so the trip (13:55 duty scheduled) is illegal. With PST, you'd still be good to go. So, you either get lucky (in this case, use 'home base time') or you don't. Of course, the opposite example can also occur (where the local time keeps you legal, but the home base time doesn't).

With option 2, don't delay the flight, if that 30+ hour layover in EWR was necessary to keep your schedule legal, then you're going to have to get that rest sometime, so, either a RSV crew will have to be burned, or your schedule will have to be modified. Depending on how long ago you last got a 30+ hour rest, option 2 might not even be available.

The option the example seems to stress - don't delay the flight, but the EST vs. PST creates an issue - that's impossible, b/c the 30 hours is not dependent on time zone, only the show time, and the show time didn't change.

Since we agree that a LAX crew is both 'acclimated' and has not changed 'theater' in EWR , lets look at our disagreement:
Yeah, that 30 hour rest thing and the start of a new FDP. Let’s look at that. From your un-cited reference:
That bolded part is the source of my confusion.
That is the only mention in FAR 117 of a 30 hour rest period, and, in fact, the only use of the number "30" in FAR 117. While a new FDP does indeed start after a 30 hour rest, whether you are starting a ‘new’ FDP or continuing a current one is immaterial to what time zone you are required to use when determining FDP limits in Table B (duty period limits, based on show time, for an unaugmented crew). It merely requires a ‘look-back’ of 30 hours of rest in 168 hours, just like the current ‘look-back’ of 24 hours of rest in 7 calendar days. Once you get the 30 hour rest, you are good to go for another 138 consecutive hours (168-30) without a 30 hour rest period (just like now you are good to go for another 6 calendar days without a 24 hour break).Whether you use LAX time or EWR time, 29:45 of rest is still 29:45 of rest, no matter how many time zones you’ve crossed prior to beginning it. Whether you are starting a new FDP or continuing a current one is irrelevant. It does not give relief to compliance with Table 2, just like today, whether you are coming off 24 hours of rest or 8 hours of rest and no matter what time zone you are in, your FAR max duty day is still 16 hours.

So, just like ALPA says (and FAR § 117.13(b)(2) . . . and B.2. on page 3 of the FAA’s response to A4A), an airline can use ‘Local time’ for the entire trip, or can use ‘home base time’ for the entire trip. The airline does not have to use local time, but would then be required to use ‘home base time’ for the entire trip. This would be true whether the pilot gets a 31 hour rest, a 29:45 rest, or a 10 hour rest – the minimum allowed.

I can't find any support for your '30 hour rest = new FDP = implications for Table B (for an unaugmented pilot that operates within 'the lower 48'). If you have one: