H1B renewal Start date

My current I797 is valid until Feb 2023. My employer is filing my renewal in pp next month (Aug 2022). What will be the start date for my renewal. Will it be the end of my prev. I797 (Feb 2023) or will the start date be the approval date (Aug/Sep 2022)?

Background: I have a Visa stamping appointment in UAE for Sep 2022. US consulate will only stamp visa 90 days before start date. If my renewal start date is Feb 2023 then I cannot get a visa stamp in Sep 2022 for my new extension. Has anyone faced this?

Start date will be end of my prev. I797 (Feb 2023) .

I dont think the 90 days rule apply to an approved extension of status petition. You can submit current and the new EOS approval and the consulate should approve the visa for 3 years from the date of stamping.

Thank you, Kalpesh. Appreciate your response!