Travel abroad between online application and in-person appointment

[mashayekh_hosein]

Hi,

I am applying for a new tier-2 visa for a change of employer. I am aware that I have to apply online, and then I want to book a premium appointment for in-person. My questions are:

1- Whether I can travel abroad after submitting the online application and booking the appointment and before I actually attend the appointment to present my documents?

2- When is the date of my application? The online submission or in-person appointment?

Many Thanks for your guidance.

Hosein