Hi,
I understand you are right as knowing what timezone the prospects live in would be really very helpful.
But what you should also know is that when a prospect fills out the form then he/she enters the country and state where they are.
Anytime i get a missed sign up or a new prospect email i get all the complete details about the person.
Including their country and state where they live in so it is not hard for me to look it up on what the time difference is online.
Hope this helps.
Regards,
Aftab Husain
www.infiniteincome.ws