H1B visa dropbox appointment

Hi All,

I am having hard time to book H1b visa dropbox appointment.
I am trying to book from past 5 days unsuccessfully. It shows no slots available.

From your experience, after how many days they generally open visa slots?
Is there any pattern like every Saturday or Sunday?

Is there any website or whatsapp or telegram group where we can track the slots.

Any pointers are highly appreciated.

Thanks in advance,