onTimeRangeSelected(args) not passing values

The client-side event-handling API has two modes that can be switched using .api property:

http://api.daypilot.org/daypilot-scheduler-api/

All DayPilot versions that include an integrated server-side part (ASP.NET WebForms, MVC, Java) use .api=1. These versions will support api=2 in the near future but at this moment you can only use api=1 (api=2 will break the event handlers set from the server side).

You should check the bottom of the API doc page for the api=1 syntax:

http://api.daypilot.org/daypilot-scheduler-ontimerangeselected/

The standalone JavaScript version uses .api=2 by default and the following example will work. It is copied from the demo at http://javascript.daypilot.org/demo/scheduler/

    dp.onTimeRangeSelected = function (args) {
        var name = prompt("New event name:", "Event");
        dp.clearSelection();
        if (!name) return;
        var e = new DayPilot.Event({
            start: args.start,
            end: args.end,
            id: DayPilot.guid(),
            resource: args.resource,
            text: name
        });
        dp.events.add(e);
        dp.message("Created");
    };