As said above, domestically they cannot schedule you back more than 24hr late domestically, 48hr late internationally. LP1 is 150% and calculated as a brand new trip (paid on min pay per duty period, block or trip/duty rig whichever is greater) from the original BTB, but only if you actually get back more than 4hr late. If you are ACTUALLY more than 25hr late domestically or 50hr late internationally, you get LP2 of 250%. If the cause of being late is weather or mechanical, LAP is calculated from 4hr after BTB, not original BTB.

Reserves may be extended up to the end of their first day off domestic, or end of their second day off international for the same 150% LP1 as above. If a reserve ends up getting back later than permitted, they only get 150% LAP but the additional days extended get restored as days off.