add additional data to $form.serialize() ajax post?
try this:
$.ajax({ type: 'post', url: '/process/somepage.php', data: $form.serialize() + '&hours=' + JSON.stringify(selectedHours), dataType : 'json'}).done(function (response) {... and so on...data sended are just a URL encoded string. You can append other value with a simple concatenation.
Perhaps a better solution to this might be to use jQuery's serializeArray, as suggested by this answer:
var data = $form.serializeArray();data.push({name: 'hours', value: selectedHours});$.post('/process/somepage.php', data).done(doSomething);This solution might be preferable because it avoids manually constructing a serialized data string, instead opting to passing the data on for jQuery to deal with.