jquery when/then (also when/done) not waiting

This is not be the OPs issue, but I had something similar happen and it was because I was calling $.when(...) incorrectly by passing an array of promises.

Per the documentation for jQuery.when if you want to wait for multiple Deferred objects you must make the call as such:

$.when( d1, d2 ).then(....);

That means that if you have multiple deferred objects in an array you should use apply(...), otherwise $.when will not work properly. So your call for an array of deferred objects would look like this:

$.when.apply(this, arrayOfDeferred).then(....);

Here is a JS Fiddle demonstrating this:

https://jsfiddle.net/Lvo4hrez/11/

function GetHours() {
    return $.ajax({
        ...
    });
};

$.ajax() returns a Promise. $.when() takes a collection of Promises, and returns a promise that completes when all the input promises complete .then() is a method on Promise (in this case, the wrapper Promise that when() created) that calls it's first function arg when the promise resolves with success.

so, your GetHours needs to return a Promise that when() can wrap, and you call the then() on. you could actually skip the when() part and just call .then on the return from GetHours.

you aren't getting an error because .when() also takes any old object, and if it doesn't implement the Promise interface, it just treats it like an already-completed Promise.