eg: It can be Sunday thru Saturday
var dateOfWeek = "Wednesday"
var timePickerStart = $find("<%= RadDateTimePickerWednesdayStart.ClientID %>");
or I can use:
var timePickerStart2 = document.getElementById("ctl00_TabContent_RadWindow1_C_RadDateTimePicker" + dateOfWeek + "Start");
timePickerStart2.set_enabled(true);
but I receive error "Microsoft JScript runtime error: Object doesn't support property or method 'set_enabled".
3 Answers, 1 is accepted

I'm assuming you have a RadTimePicker for each day of the week. If so, you can change the id by doing this:
var
dateOfWeek =
"Wednesday"
;
var
baseId =
"<%= RadDateTimePickerMondayStart.ClientID %>"
;
var
timePickerStart = $find(baseId.replace(
"Monday"
,dayOfWeek));
This assumes that they all follow the same naming convention.
I hope that helps.

on the VB.net side the following code only produce the date ("2013-1-30"), no time. It's suposed to produce "2013-1-30-18-00-00":
SelectedDateEnd
Dim SelectedDateEnd as Date = RadDateTimePickerWednesdayEnd.DateInput.SelectedDate.Value
My aspx page look like:
var timeViewStart = document.getElementById("ctl00_TabContent_RadWindow1_C_RadDateTimePicker" + dateOfWeek + "Start_dateInput_display");
var timeViewEnd = document.getElementById("ctl00_TabContent_RadWindow1_C_RadDateTimePicker" + dateOfWeek + "End_dateInput_display");
var timeViewStartWrapper = document.getElementById("ctl00_TabContent_RadWindow1_C_RadDateTimePicker" + dateOfWeek + "Start_wrapper");
var timeViewEndWrapper = document.getElementById("ctl00_TabContent_RadWindow1_C_RadDateTimePicker" + dateOfWeek + "End_wrapper");
timeViewStartWrapper.style.visibility = "visible";
timeViewEndWrapper.style.visibility = "visible";
var baseIdStart = "<%= RadDateTimePickerSundayStart.ClientID %>";
var timePickerStart = $find(baseIdStart.replace("Sunday", optionDate));
var baseIdEnd = "<%= RadDateTimePickerMondayEnd.ClientID %>";
var timePickerEnd = $find(baseIdEnd.replace("Sunday", optionDate));
timePickerStart.set_enabled(true);
timePickerEnd.set_enabled(true);
if (null != timeViewStart) {
timeViewStart.innerHTML = "12:00 A";
timeViewEnd.innerHTML = "6:00 P";
var timeViewStartValue = document.getElementById("ctl00_TabContent_RadWindow1_C_RadDateTimePicker" + dateOfWeek + "Start_dateInput");
var timeViewEndValue = document.getElementById("ctl00_TabContent_RadWindow1_C_RadDateTimePicker" + dateOfWeek + "End_dateInput");
var date = timeViewEndValue.getAttribute('value');
var dateSubstring
var dateStringOnly = DateWednesday.format("yyyy-mm-dd");
if (date != null) {
dateSubstring = date.substring(0, 11);
}
else {
dateSubstring = dateStringOnly;
}
timeViewStartValue.setAttribute("value", dateSubstring + "00-00-00");
timeViewEndValue.setAttribute("value", dateSubstring + "18-00-00");
timeViewStart.disabled = true;
timeViewEnd.disabled = true;
}
When working with RadControls on the client you should use their client-side API instead of only attributes of the pure HTML elements. This is needed because there is a lot of code working behind the public API we provide. The list with the RadDatePicker's client-side API is available here: http://www.telerik.com/help/aspnet-ajax/calendar-client-side-rad-datepicker.html.
All the best,
Marin Bratanov
the Telerik team