How to close sign-ups at a deadline

You can close the whole form at a specific date and time. After it passes, the page shows a clear "Sign-ups are closed" message and no one can submit, even with the page already open. It's enforced on the server, so a late submission can't slip through.

Steps

1. In chat, say when it should close (for example, "close sign-ups at noon on July 1", "deadline is Friday at 5pm", or "no sign-ups after the 15th").
2. While the form is open, it shows when sign-ups close so people know.
3. Once the time passes, the form switches to a "Sign-ups are closed" notice on its own.

The deadline closes the whole form (not one option), and a date with no time closes at the end of that day. To reopen it, just ask in chat to remove or change the deadline. The people who already signed up are not affected.