If you do not have to use multiview calendars, then you can set autopostback to false for the three calendar instances and the following works nicely to navigate by month/year in each direction. (see code that follows).
use multiview calendars, then you will have to set triplets containing the focused date for each calendar client side, save the values in hidden field(s), and pass this to the code behind and reset the calendars on Page_Load. And, in order to accomplish this, you would need to determine, server-side, which button was clicked. You can refer to this link for more information how this can be accomplished:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Default" %>
<
head
runat
=
"server"
>
<
title
></
title
>
<
telerik:RadStyleSheetManager
id
=
"RadStyleSheetManager1"
runat
=
"server"
/>
</
head
>
<
body
>
<
form
id
=
"form1"
runat
=
"server"
>
<
telerik:RadScriptManager
ID
=
"RadScriptManager1"
runat
=
"server"
>
<
Scripts
>
<%--Needed for JavaScript IntelliSense in VS2010--%>
<%--For VS2008 replace RadScriptManager with ScriptManager--%>
<
asp:ScriptReference
Assembly
=
"Telerik.Web.UI"
Name
=
"Telerik.Web.UI.Common.Core.js"
/>
<
asp:ScriptReference
Assembly
=
"Telerik.Web.UI"
Name
=
"Telerik.Web.UI.Common.jQuery.js"
/>
<
asp:ScriptReference
Assembly
=
"Telerik.Web.UI"
Name
=
"Telerik.Web.UI.Common.jQueryInclude.js"
/>
</
Scripts
>
</
telerik:RadScriptManager
>
<
telerik:RadCodeBlock
ID
=
"RadCodeBlock1"
runat
=
"server"
>
<
script
type
=
"text/javascript"
>
function NavigatePrevYear() {
var calendar = $find("<%=RadCalendar1.ClientID%>");
var triplet = [calendar.FocusedDate[0] - 1, calendar.FocusedDate[1], calendar.FocusedDate[2]];
calendar.navigateToDate(triplet);
var calendar2 = $find("<%=RadCalendar2.ClientID%>");
var triplet = [calendar2.FocusedDate[0] - 1, calendar2.FocusedDate[1], calendar2.FocusedDate[2]];
calendar2.navigateToDate(triplet);
var calendar3 = $find("<%=RadCalendar3.ClientID%>");
var triplet = [calendar3.FocusedDate[0] - 1, calendar3.FocusedDate[1], calendar3.FocusedDate[2]];
calendar3.navigateToDate(triplet);
}
function NavigatePrevMonth() {
var calendar = $find("<%=RadCalendar1.ClientID%>");
var triplet = [calendar.FocusedDate[0], calendar.FocusedDate[1] - 1, calendar.FocusedDate[2]];
calendar.navigateToDate(triplet);
var calendar2 = $find("<%=RadCalendar2.ClientID%>");
var triplet = [calendar2.FocusedDate[0], calendar2.FocusedDate[1] - 1, calendar2.FocusedDate[2]];
calendar2.navigateToDate(triplet);
var calendar3 = $find("<%=RadCalendar3.ClientID%>");
var triplet = [calendar3.FocusedDate[0], calendar3.FocusedDate[1] - 1, calendar3.FocusedDate[2]];
calendar3.navigateToDate(triplet);
}
function NavigateNextMonth() {
var calendar = $find("<%=RadCalendar1.ClientID%>");
var triplet = [calendar.FocusedDate[0], calendar.FocusedDate[1] + 1, calendar.FocusedDate[2]];
calendar.navigateToDate(triplet);
var calendar2 = $find("<%=RadCalendar2.ClientID%>");
var triplet = [calendar2.FocusedDate[0], calendar2.FocusedDate[1] + 1, calendar2.FocusedDate[2]];
calendar2.navigateToDate(triplet);
var calendar3 = $find("<%=RadCalendar3.ClientID%>");
var triplet = [calendar3.FocusedDate[0], calendar3.FocusedDate[1] + 1, calendar3.FocusedDate[2]];
calendar3.navigateToDate(triplet);
}
function NavigateNextYear() {
var calendar = $find("<%=RadCalendar1.ClientID%>");
var triplet = [calendar.FocusedDate[0] + 1, calendar.FocusedDate[1], calendar.FocusedDate[2]];
calendar.navigateToDate(triplet);
var calendar2 = $find("<%=RadCalendar2.ClientID%>");
var triplet = [calendar2.FocusedDate[0] + 1, calendar2.FocusedDate[1], calendar2.FocusedDate[2]];
calendar2.navigateToDate(triplet);
var calendar3 = $find("<%=RadCalendar3.ClientID%>");
var triplet = [calendar3.FocusedDate[0] + 1, calendar3.FocusedDate[1], calendar3.FocusedDate[2]];
calendar3.navigateToDate(triplet);
}
</
script
>
</
telerik:RadCodeBlock
>
<
div
>
<
table
>
<
tr
>
<
td
>
<
telerik:RadButton
ID
=
"RadButton1"
runat
=
"server"
AutoPostBack
=
"false"
Text
=
"<<"
OnClientClicked
=
"NavigatePrevYear"
>
</
telerik:RadButton
>
<
telerik:RadButton
ID
=
"RadButton2"
runat
=
"server"
AutoPostBack
=
"false"
OnClientClicked
=
"NavigatePrevMonth"
Text
=
"<"
>
</
telerik:RadButton
>
<
telerik:RadButton
ID
=
"RadButton3"
runat
=
"server"
AutoPostBack
=
"false"
OnClientClicked
=
"NavigateNextMonth"
Text=">" >
</
telerik:RadButton
>
<
telerik:RadButton
ID
=
"RadButton4"
runat
=
"server"
AutoPostBack
=
"false"
Text=">>" OnClientClicked="NavigateNextYear" >
</
telerik:RadButton
>
</
td
>
</
tr
>
<
tr
>
<
td
>
<
telerik:RadCalendar
ID
=
"RadCalendar1"
runat
=
"server"
AutoPostBack
=
"false"
ShowRowHeaders
=
"false"
FocusedDate
=
"1/1/2012 12:00:00 AM"
>
<
SpecialDays
>
<
telerik:RadCalendarDay
Repeatable
=
"Today"
Date
=
""
ItemStyle-CssClass
=
"rcToday"
>
<
ItemStyle
CssClass
=
"rcToday"
></
ItemStyle
>
</
telerik:RadCalendarDay
>
</
SpecialDays
>
</
telerik:RadCalendar
>
</
td
>
<
td
>
<
telerik:RadCalendar
ID
=
"RadCalendar2"
runat
=
"server"
AutoPostBack
=
"false"
ShowRowHeaders
=
"false"
FocusedDate
=
"1/1/2013 12:00:00 AM"
>
<
SpecialDays
>
<
telerik:RadCalendarDay
Repeatable
=
"Today"
Date
=
""
ItemStyle-CssClass
=
"rcToday"
/>
</
SpecialDays
>
</
telerik:RadCalendar
>
</
td
>
<
td
>
<
telerik:RadCalendar
ID
=
"RadCalendar3"
runat
=
"server"
AutoPostBack
=
"false"
ShowRowHeaders
=
"false"
FocusedDate
=
"1/1/2014 12:00:00 AM"
>
<
SpecialDays
>
<
telerik:RadCalendarDay
Repeatable
=
"Today"
Date
=
""
ItemStyle-CssClass
=
"rcToday"
/>
</
SpecialDays
>
</
telerik:RadCalendar
>
</
td
>
</
tr
>
</
table
>
</
div
>
</
form
>
</
body
>
</
html
>