H1B visa online appointment

[careergirl]

Hi,
I am currently working in US. I am planning to appear for the H1B visa stamping in Mumbai sometime in first week of Dec'09.
Does anyone know when is the earliest one can book the online visa appointment ?
I am trying to book it now for Dec, and somehow it is not allowing me to do so.

This is because the process in Mumbai is a bit different and time consuming, since I will also have to submit some documents about 5 days before the visa date.

Thank you for your inputs.

-careergirl