BB5,
Is it ok to ignore the governing documents? - No
Is a holiday weekend a good time to get maximum participation at a meeting? - No.
I believe that your Board is probably looking at the reality of getting a forum and maximum participation. The correct way to do this would be to change the Bylaws to specify the month the meeting should be held vs the actual day.
What happens if they don't hold the meeting on the day designated? - Nothing.
Per
Missouri Nonprofit Corporation Act, 355.231: "The failure to hold an annual or regular meeting at a time stated in or fixed in accordance with a corporation's bylaws does not affect the validity of any corporate action."
I am of the understanding that most States corporate laws have similar language but anyone not in Missouri should check.
I would recommend that you propose a bylaw amendment at the next annual meeting to change this requirement then the membership can actually vote on it the following year.
Hope this helps,
Tim