Try this
- Name the windows relevant to your shared plan and distinguish firm commitments from estimates.
- Use a simple unavailable label where the reason is private. Do not turn the check-in into a requirement to justify the rest of the day.
A worked example
“I can talk before nine, then I’ll be unavailable until lunch.”
An invented example to adapt, not a real exchange or a script you have to follow.
Before you leave it here
Distinguish an availability estimate from a promise to respond at an exact minute.