A person writes weekends only but is free on occasional Saturdays rather than every weekend. Someone seeking a weekly Friday meeting could read more availability than exists.
Wording you can adapt
“Occasional Saturdays suit me best, usually with a little notice. Weekdays generally don’t work.”
What this clears up
Pair the broad weekend label with likely frequency. This helps distinguish visitor availability, alternating weekends and a regular Saturday pattern without publishing an exact personal calendar.