It isn't recognised as a word, so this isn't a spoiler.
In a previous lifetime, I worked as an air traffic controller. One of the shifts was called a daymid. A typical work schedule was
Day 1: 1600-0000
Day 2: 1300-2100
Day 3: 1000-1800
Day 4: 0700-1500
Day 5: 0000-0800
The last two were referred to as a daymid. They were difficult. The only positive thing about them was having 80 hours off or 56 hours off (alternating each week) before returning to work.
Despite a very large number of studies which show shift workers need to be kept on a steady shift, despite the requirements for air traffic controllers to meet the same physical standards as pilots, despite requirements for pilots to have a minimum rest period of 10 hours, with the opportunity for at least 8 uninterrupted sleep hours, the Federal Aviation Administration allowed this as a normal schedule. And because every other week, the schedule was move up 24 hours, a controller would, in a 14 week period work all 24 hours all 7 days (forget about making a regular commitment (e.g. coaching youth sports, taking a college course, regularly making meetings of an organisation, etc.).
I hated the work schedule. And when I asked a supervisor why we worked such a 'stupid schedule', I got one of the all-time worst responses that can be given: 'that's the way we've always done it'!
Anyway, that was the flashback prompted by the letters in the puzzle.