When is the right time to resign?

I’m currently a tech recruiter in Dubai with three years of experience. I’ve accepted an offer from a global firm, but my start date has been postponed due to my travel plans.

I haven’t resigned yet because I expect to be placed on garden leave, despite my two-month notice period.

I will be on annual leave from December 1-7 and will receive my paycheck on December 1, as I want to collect my commission before resigning; otherwise, I won’t be eligible for it.

I’m considering submitting my resignation when I return to work on December 9. I’m unsure about how long my handover will take—it could be up to two months, which feels risky since I’ve informed my new employer that I’d be available by the end of December. Typically, people transition to competitor roles quite quickly, within days or a week.

I would appreciate any thoughts or advice on how to handle this situation!