In the same way as temperature, include the humidity and solar radiation as input variables from the weather files. I'm not sure if solar radiation is available, but maybe one of the other inputs could be used to account for certain behavior.
I have had another freelancer to the tedious work of creating a spreadsheet of all of the holidays. I have shared this spreadsheet on slack in addition to a MASTER meta spreadsheet where we can match the buildings with their annual schedules and use that as daily input to the ML models