Now sorting array is hardcoded (for example in kendo.scheduler.timelineview.js) in render method:

[
    {
        field: 'start',
        dir: 'asc'
    },
    {
        field: 'end',
        dir: 'desc'
    }
]

it will be very good if you will implement this sorting inside scheduler cell (data/group field) as parameter.