Pass the main object (this) to the callbacks

[moshfeu]

Now, when you are calling to callback you get the main object like
"afterDone: function(element) {
console.log(element, "after done");
}"

[RobinHoutevelts]

+1
I was about to create my own PR.

Without the context set it's impossible to know which clockpicker fired the callback.
Although I simply added at line 354

var noop = function () {};
var isFunction = function (callbackFunction) {
    return callbackFunction && typeof callbackFunction === "function";
};

[
    'init', 'beforeShow', 'afterShow', 'beforeHide', 'afterHide',
    'beforeHourSelect', 'afterHourSelect', 'beforeDone', 'afterDone'
].forEach(function(callbackName){
    var callback = this.options[callbackName];
    callback = isFunction(callback) ? callback.bind(this) : noop;
    this.options[callbackName] = callback;
}.bind(this));

Imo it's cleaner as you don't have to change the prototype. The forEach could be replaced with a regular loop in case you need to support IE8.

Anyway, guess it doesn't matter much as this project doesn't seem to be maintained anymore. So I'll just leave it here for others to find.

[arthur-alves]

Merge this please, we need.