My wife has a work hour roster in sheets where all 13 colleagues have their hours listed so she can see when who works which day.

For sure it’s possible but it would require script to pull the dates from the sheet into the calendar.

I’d start by doing as suggested above and importing the data into your own sheet where it can be easily filtered using a query or simple filter function.

The next step would be to write some apps script code that will transfer any changes directly into calendar. It will probably need to cross check each entry in the filtered list against the calendar… or perhaps it’d be simpler to just wipe the calendar entries and reset them each time it runs.

Set it up with a trigger to run every hour or when you press a button

Interesting question. Maybe withe Query function ?

Query example : Have you tried a QUERY formula instead.. this might be an option : =QUERY(IMPORTRANGE("URL","Schedules!E2:M"), "SELECT E WHERE M CONTAINS '"&A1&"'", 0) you can use cell references so that the data that you are looking for is dynamic instead of it being hard coded in the formula...