Cancelling PN and moving to Cityfibre procedure

[#1]

Cityfibre has been activated in my street and I will be switching at the end of my contract on 29 Jan 2022

my question is what is the procedure?

I know that I have to give PN 30 days notice as  I'm switching to a provider not on openreach

so do I give notice on 29 Jan 22 or on 29 dec 21?

[#2]

It’s 14 days notice and you’ll need to call 0800 013 2632. Probably best calling 14 days before you go live with Cityfibre/the end of your contract so you don’t pay termination fees or two services simultaneously