It is possible to use a special mode where the user can select an exact position inside the target cell when moving the event (relative to other events in the target cell). 

You can use this feature to manage priority ordering.

Moving modes

Default moving mode (moving to time cell)

scheduler move event to cell

Moving to a position inside a cell

scheduler move event to position

You can enable this mode by using EventMoveToPosition property. The selected position will be available in EventMove event handler as e.Position.

You should store the position in a separate database field and use it for event sorting.

JavaScript

<div id="dp"></div>
<script type="text/javascript">
  var dp = new DayPilot.Scheduler("dp");
  dp.eventMoveToPosition = true;
  dp.onEventMoved = function(args) {
    dp.message("Event moved to position: " + args.position);
  }
  // ...
  dp.init();
</script>

ASP.NET WebForms

.aspx

<DayPilot:DayPilotScheduler runat="server" id="DayPilotScheduler1"
  ...
  EventMoveToPosition = "true"
/>

.aspx.cs

protected void DayPilotScheduler1_EventMove(object sender, DayPilot.Web.Ui.Events.EventMoveEventArgs e)
{
  // update the db here, reload events
  DayPilotScheduler1.UpdateWithMessage("Event moved to position: " + e.Position);
}

Demo

ASP.NET MVC

The target position is available in OnEventMove handler as e.Position (starting at index 0).

Example

View

@Html.DayPilotScheduler("dps_position", new DayPilotSchedulerConfig {
  BackendUrl = ResolveUrl("~/Scheduler/Backend"),
  ...
  EventMoveToPosition = true
})

Backend Controller

protected override void OnEventMove(EventMoveArgs e)
{
  // update the db here, reload events
  UpdateWithMessage("Moved to position: " + e.Position);
}

Demo