Kill MacOS Processes by Name

I have a cron job that opens a program every day at a certain time. How can I also close it with a cron job?

To open:

45 9 * * 1-5 open -a "SomeProgram"

And to close a few minutes later:

50 9 * * 1-5 killall "SomeProgram"

See man killall for more information.