Time and temperature spreadsheet schedule

There is no support for arrays and there is no easy way to achieve this.

However, you may be able to use Associated Items.

You would create Items for each room and each time period named in such a way that you can construct the name given the name of your target temperature Item. Then you can look that Item up and pull it from a Group.

However, I would sit back and consider whether that is the most appropriate solution. Perhaps you can come up with an offset that applies to all rooms when you leave (e.g. when you leave drop the temp by X degrees across the board).

Then use an offset as well for each room that gets applied across the day so at each time period you add or subtract the set offset across the board.

There are other approaches to this problem that could give you the same result without a table.