I booked flights in Sep 2016 for Jul 2017 CHS-IAD-HNL-IAD-HNL I had 16 changes throughout the roughly 8 months. 2 of the 16 were self inflicted (I class cleared) but the other 14 were all schedule changes or swapping aircraft (763 changed to 764 for return flight)

EVERY schedule change, including the I class was on a Sunday except one, when they swapped planes.

Last change was in early May, approx 60 days from flight