Scheduler Calendar to be used for Missionary Co-teachng

I am looking for a Scheduler Calendar that can be accessed by Ward Elders to signup for Co-teaching Visits with our Ward Missionaries. Since we share our missionaries between two different Wards, I would need to block off both certain days and certain hours. I would also like it to email both the Missionaries and Elders that signed up a reminder of the appointment so both can be prepared. Best to setup for 1 to 2 months at a time. Any suggestions?