The poor woman is so nice and so accommodating. She wants to make sure all friends and family can gather as often as possible for these bashes. Finding a date that suits the schedules of many is difficult. Thanksgiving had never been moved before, but she has knee surgery lined up for Wednesday. OK, so there it is. I'm fine with breaking free of the arbitrary holidays set up by churches and governments.
From a cosmologists point of view, our local anniversaries only coincide with an approximation of where the Sun is in relation to the Earth.