Notifications, pop-ups and reminders

Notifications, pop-ups and reminders

im totally new to this, and im setting up Zoho desk with a few Test Tickets.  i am setting up reminders.  some are a day Before the due date, some are ON a specific day and time.  
all the reminders have come and gone without any notifications.  no pop-up.  however, i DID get an email reminder, (the "day-before" one) but still no pop-up within Zoho.
(and as a side-topic, id like to change where the reminder email goes too, and i dont know how)

i also added a Test reminder to the Activities Tab at the top, rather than a specific ticket.  in our scenario, we have maintenance contracts and every few months i need a reminder that we owe them a site visit, as per our contract.  i set up the reminders exactly the same way.  the time and day came and went without any notifications.  no email, no pop-up within Zoho.
am i doing something wrong?  is something not set up correctly?
i would also like a way to get notifications when a ticket goes past its due date.  i dont see any option for that.

thanx
Jim