

We could have had that, but when some people who might have succeeded tried to establish a proper standard for Markdown in 2014 the original inventor threw a tantrum so they backed down and it never went anywhere.
https://blog.codinghorror.com/standard-markdown-is-now-common-markdown/

That’s quite the drastic conclusion to draw from people telling you when they are available (and that not being literally always) to help you for something you most like presented as not critical or dramatic when you asked them. Do you seriously expect people to preemptively cancel all their existing plans based on a hunch you might judge their whole character and the sincerity of your friendship on the sole trigger of a seemingly innocent “hey, when would you be available to help me move?”?
If you want to at least give people a chance to adjust, don’t ask “when are you available?”, instead try “[date] is when I want to move, can you fit helping me then into your schedule?” at least a few weeks ahead of that date.