Javascript – Function's argument being "undefined"

When I try to call the function I created (see code below), it throws an error stating that "Jon is not defined". Why is it saying that? How is an argument for a function I’m trying to call undefined?

function greeting(person, hour, minutes) {
    time = ((hour+12)*1000)+minutes
    if (person = "Count Dooku") {
        console.log("I'm coming for you, Dooku!")
    }
    else {
        console.log("Good day, " + person + "! " + "It is currently" + time)
    }
}

console.log(greeting(Jon, 1, 13))

And the error is this:

Uncaught ReferenceError ReferenceError: Jon is not defined
    at <anonymous>         
 
    at Module._compile (node:internal/modules/cjs/loader:1267:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1321:10)
    at Module.load (node:internal/modules/cjs/loader:1125:32)
    at Module._load (node:internal/modules/cjs/loader:965:12)
    at executeUserEntryPoint (node:internal/modules/run_main:83:12)
    at <anonymous> (node:internal/main/run_main_module:23:47)
Process exited with code 1'

I tried fiddling around in trace playground to see if I could alter the code and get it to work, but I’m pretty certain this is the basic setup for creating and calling a function. I don’t even know what I would change.

I am using VS Code if that makes any difference. I don’t have much experience with it, so if it’s some missing extension or something I would have no idea.