I missed this when it was first posted.
I do not remember anymore when this was added. But I think the iCalendar binding was available in OH 2.5 (seems to be in the docs so yes). This lets you use any iCal calendar to create events in OH. That is the most direct approach to achieve this.
The supported Channels on the 2.5 version of the binding are somewhat limited but the latest version supports a few more. But I don’t think even it gets the list if invitees so you’d have to encode that into the text of the event somehow and parse the people and their preferred temp ranges from that.
I don’t think this is really all that hard to achieve, assuming you can figure out the algorithm to choose the appropriate temperature. The calendar stuff is already done for you.
There’s also a third partyextension (not really a plugin) that provides a scheduler interface for OH. That might be worth looking at.
There is also a “Time of Day” state machine which I originally came up with way back in OH 1.6 days and have kept up. Today it’s a rule tempalte that can be just installed and configured. But this can be used to schedule regular time of day based events. It even uses ephemeris so you can have different time of day events for holidays than work days (for example).
Beyond that, the existing rules for HestiaPi are a state machine approach as well, though admittedly a bit more comoplicated than I would have liked. I always wanted to go back and simplify but most of what I need to do so are only available in newer versions of OH.
This is built into OH since 3.2 (IIRC) through Ephemeris. It supports not only week day and weekend, but holidays as well as the ability to define custom types of days (e.g. trash day, birthdays). It pulls the default list of holidays based on your regional settings.