Moving visa appointment to earlier date

[deepikapr]

Hi,

I have booked a visa appointment for my parents on first week of march. However, I want to prepone the appointment to some date earlier if at all new dates are available in feb. When i booked the dates, the earliest available appointment was in march. Are there any chances that the Chennai consulate would release dates earlier than what was mentioned before. I saw that happening with New Delhi Consulate: when I booked, the earliest available date was on 28/2, now the earliest available date is 22/2.
I read that the process of moving the appointment to an earlier date is to first cancel the current appointment and then book a new appointment. But, I'm afraid that even if I see new dates in feb and cancel my first appointment, what if the new dates get over by the time I cancel the old appointment and immediately book the new one. In that case I will be left with none. Has anyone experienced such problems while moving their appointment to an earlier date? Is it possible that dates get filled in such short duration( time for cancelling + time for booking new appt.)
Please advise.

Thanks a lot in advance.

[immihelp]

There is no way for anyone to predict the chances of earlier dates opening.

Your concern is real. That is the risk you take while trying to book an earlier appointment.