So far, the list is global, so it does not support multiple users on a single connection.
If necessary, restart the server to start the schedule again.

Feel free to use the code and suggest improvements, point errors and what is needed.

What is rpc?

Remote Procedure Call (RPC) is a protocol that one program can use to request a
service from a program located in another computer on a network without having to
understand the network's details. A procedure call is also sometimes known as
a function call or a subroutine call.

RPC uses the client-server model. The requesting program is a client and the service
providing program is the server. Like a regular or local procedure call, an RPC is
a synchronous operation requiring the requesting program to be suspended until the
results of the remote procedure are returned. However, the use of lightweight
processes or threads that share the same address space allows multiple RPCs to be
performed concurrently.

Font: http://searchmicroservices.techtarget.com/definition/Remote-Procedure-Call-RPC