Captive portal files location?

[Daves_nt_here]

Does anyone know where the templates are located in OPNsense?

I have 2 templates for a company's public wifi. One for when they are open and one for when they are closed.
As I can't see any way of setting a timer in the GUI to switch them, I thought of just uploading both sets of templates then use a cron job to rotate them.

Any ideas?