How would I setup a reminder on the due date of a task that either sends an email to the assignee or pops up a message?

So for example I will setup a task that requires someone to follow up with a Lead based on a due date, how will the person know that the due date has arrived? Will Zoho email them on the due date and if so at what time of the day will this email be sent out?

I hope I am making sense.