Passport appointment reschedule process -India, permanent resident

I don't want others to suffer hence posting this. In case, you want to reschedule your passport appointment, you don't need to visit the passport office on the day of your original appointment.

You will be allowed to reschedule it from 6pm on the day of the appointment till the next morning. Prior to it, you will keep getting this message online : " passport seva says undefined".

I didn't know this and had to visit the kendra just to hear this, because I kept trying to reschedule the appointment online.