Switching Visas: Does Application Submission mean the Online Application or only after Biometrics?

I am currently on a Tier 4 visa switching into a Tier 2. My visa expires 23/03/2020. I have just received my CoS today, following which I submitted and paid for the application online. Now I'm looking into booking the appointment to have my biometrics done, but the available appointments before/on the 23rd are either really far, or too expensive (€200 at Mark Lane).

On the GOV website, it says that once I've applied, I am allowed to stay while waiting for a decision. My question is - at this point, does it mean that I have already applied (given I've paid both visa and IHS fees)? Or does it only count after I attend the biometric appointment? I'm asking because if it means I've already applied, then I can try to book a free slot after the 23rd... (kinda low on funds after paying for the application).

Thank you.

Date of application is the date your submit and pay online. Date of biometrics is irrelevant.

Oo thank you very much for your help!

I tested my luck and looked for appointments again this morning and I found a free one at Croydon on Monday (the 23rd)! So it's all good