Why the month moves
Canadian chapter pages still describe GMID as an April date. Global virtual editions have used 30 March (2023) and 11 April (2024 Michigan chapter listing). The field does not own a fixed public holiday.
The drift is administrative. A twelve-hour stream wants a weekday that works in several zones. A local breakfast wants a date the mayor can attend. Those two clocks are not the same machine.
If you are booking a room or a camera, read the year on the chapter site. Do not trust a paragraph written for a previous spring.