(complement to my previous post)

It is like handling is on 'HoldForever' and not on 'Javascript' with Firefox, very strange.

I did a very quick test with both DayPilotCalendar and DayPilotScheduler (I just modified TimeRangeSelectedHandling in the Demo/Calendar/Default.aspx and Demo/Scheduler/Default.aspx). It seems to be working fine. Maybe it appear only under specific conditions. Can you post your DayPilot declaration from the ASPX file?

Here it is :

<%@ Register Assembly="DayPilot" Namespace="DayPilot.Web.Ui" TagPrefix="DayPilot" %>

<DayPilot:DayPilotCalendar ID="DayPilotCalendar1" runat="server" Width="" BusinessBeginsHour="8" CellHeight="15" CellsPerHour="6" DataAllDayField="Journee" DataEndField="DateFin" DataStartField="DateDebut" DataTagFields="DateDebut, ID" DataTextField="DateDebut" DataValueField="ID" Days="6" EventClickHandling="Edit" EventClickJavaScript="alert('Tag[&quot;name&quot;]: ' + e.tag('name'));" EventDeleteHandling="JavaScript" EventDeleteJavaScript="if (confirm('Voulez-vous vraiment effacer \'' + e.text() + '\' ?')) dpc1.eventDeleteCallBack(e);" EventEditHandling="CallBack" EventSelectHandling="CallBack" HeightSpec="BusinessHoursNoScroll" LoadingLabelText="Chargement..." TimeFormat="Clock24Hours" TimeRangeSelectedHandling="JavaScript" OnTimeRangeSelected="DayPilotCalendar1_TimeRangeSelected" style="left: -181px; top: 94px" ContextMenuSelectionID="DayPilotMenu1" OnTimeRangeMenuClick="DayPilotCalendar1_TimeRangeMenuClick" ClientObjectName="dpc1" TimeRangeSelectedJavaScript="_handleWisely(event.type, start.toGMTString(), end.toGMTString());">
</DayPilot:DayPilotCalendar>