How can I find out when a friend will be buried at the Cemetery?

They should let you know. try calling them to find out more information

The family will receive that information and will have to provide it to you.

The family should receive notification shortly after the passing of your friend. My in-laws neighbor passed away last summer and it wasnt for about a month (I think) after that that he was buried in the temporary plots. His permanent resting place is sometike this year. You may be able to check the kiosk at the front entrance foe more information (if you have access to it).