ItemStyle

[Terje]

Hi,
I am trying to visualize the fact that some dates are unavailable. I first tried to do this in Calendar_DayRender, but I was only able to disable the dates, not colorize them.

I then tried Calendar_PreRender, and added all unavailable dates (with formatting) into the calendars SpecialDays. What happened then was
1. still only disabled, no color.
2. when I go to next month, the backcolor appears. it then stays, and works ok.
3. ForeColor is never set. It seems that <span> overrides the styling. css for span is set by Telerik.

Any suggestions on how to fix this?

[Shinu]

Hi Terje ,

In order to change the background color of RadCalendar from code behind please try the following C# code snippet.

C#:

protected void rcalendarDemo_PreRender(object sender, EventArgs e)
{
    rcalendarDemo.CalendarTableStyle.BackColor = System.Drawing.Color.SeaGreen;
}

To change the ForeColor as a workaround please try the below CSS.

CSS:

.RadCalendar .rcRow a
{
    color : Red !important;
}

Thanks,
Shinu.

[Terje]

Hi Shinu,

Thank you for your reply.

My problem is that I want to change the colours on some dates, not the whole calendar.

Here is my code:

01.protected void Calendar_PreRender(object sender, EventArgs e)
02.{
03.    if (_blockings == null && _bookings == null) return;
04.    var cal = (RadCalendar) sender;
05.    cal.CalendarTableStyle.BackColor = Color.SeaGreen;
06.    cal.SpecialDays.Clear();
07.    cal.SpecialDays.AddRange(BlockedDates());
08.    cal.SpecialDays.AddRange(BookedDates());
09.}
10.
11.private RadCalendarDay[] BlockedDates()
12.{
13.
14.    var cal = new List<RadCalendarDay>();
15.    foreach (var blocked in _blockings)
16.    {
17.        if (blocked.From_date == null || blocked.To_date == null) continue;
18.        for (var day = blocked.From_date.Value; day < blocked.To_date.Value; day = day.AddDays(1))
19.        {
20.            cal.Add(FormatDate(day, Color.DarkOrange, Color.White));
21.        }
22.    }
23.    var days = cal.ToArray();
24.    return days;
25.
26.}
27.
28.private RadCalendarDay[] BookedDates()
29.{
30.    var cal = new List<RadCalendarDay>();
31.    foreach (var booking in _bookings)
32.    {
33.        if (booking.From_date == null || booking.To_date == null) continue;
34.        for (var day = booking.From_date.Value; day < booking.To_date.Value; day = day.AddDays(1))
35.        {
36.            cal.Add(FormatDate(day, Color.DarkRed, Color.White));
37.        }
38.    }
39.    var days = cal.ToArray();
40.    return days;
41.}
42.
43.private RadCalendarDay FormatDate(DateTime day, Color backColor, Color foreColor)
44.{
45.            var calDay = new RadCalendarDay {Date = day, IsSelectable = false, IsDisabled = true};
46.            calDay.ItemStyle.BackColor = backColor;
47.            calDay.ItemStyle.ForeColor = foreColor;
48.    return calDay;
49.}

[Shinu]

Hi Terje,

The best approach for adding days to the SpecialDays collection is on Page_Load event. Please have a look into the below code snippet which works fine at my end.

C#:

public DateTime[] specialDates = { DateTime.Now, DateTime.Now.AddDays(-2), DateTime.Now.AddDays(2) };
protected void Page_Load(object sender, EventArgs e)
{
    List<RadCalendarDay> myDays = new List<RadCalendarDay>();
    foreach (DateTime date in specialDates)
    {
        RadCalendarDay oneDay = new RadCalendarDay();
        oneDay.Date = date;
        oneDay.ItemStyle.CssClass = "special-days";
        myDays.Add(oneDay);
    }
    rcalendarDemo.SpecialDays.AddRange(myDays.ToArray());
}

CSS:

.special-days a
{
    color: Red !important;
    background-color: Black !important;
}

Thanks,
Shinu.

[Terje]

Hi again, and thank you for trying :)

If you try to combine your answers, then you will see my dilemma. I am not able to put colours to a disabled date. I would also like to be able to have different colours for different meanings. Ex (red for occupied, orange for blocked, gray for unavailable).

Thanks,

Terje K.

[Shinu]

Hi Terje,

Please have a look into the below code snippet to style the disabled day in a RadCalendar.

ASPX:

<telerik:RadCalendar ID="rcalendarDemo" runat="server">
    <DisabledDayStyle CssClass="blocked" />
</telerik:RadCalendar>

C#:

public DateTime[] blocked = {  DateTime.Now.AddDays(-3), DateTime.Now.AddDays(3) };
protected void Page_Load(object sender, EventArgs e)
{
    List<RadCalendarDay> blockedDates = new List<RadCalendarDay>();
    foreach (DateTime date in blocked)
    {
        RadCalendarDay oneDay = new RadCalendarDay();
        oneDay.Date = date;
        oneDay.IsDisabled = true;
        blockedDates.Add(oneDay);
    }
    rcalendarDemo.SpecialDays.AddRange(blockedDates.ToArray());
}

CSS:

.blocked a
{
    color: Orange !important;
}

Hope this will helps you.
Thanks,
Shinu.

[Terje]

Hi again Shinu.

Very nice, but this will not make it possible to have different colors for different meanings. I did get it to work by using template, but somehow the ToDate_Calendar looses its color when I ​select a date in FromDate_Calendar.

Here is my code.

01.<telerik:RadCalendar ID="FromDate" RangeMinDate="<%# DateTime.Today %>" OnDayRender="Calendar_DayRender" runat="server" SelectedDate="<%# DateTime.Today %>" Enabled="False"
02.                            EnableAriaSupport="True" EnableShadows="True" AutoPostBack="True" EnableMultiSelect="False" OnSelectionChanged="RadCalendar_SelectionChanged" ShowOtherMonthsDays="False">
03.                            <CalendarDayTemplates>
04.                                <telerik:DayTemplate ID="BlockedTemplate0" runat="server">
05.                                    <Content>
06.                                        <div class="blocked">{DayOfMonth}</div>
07.                                    </Content>
08.                                </telerik:DayTemplate>
09.                                <telerik:DayTemplate ID="BookedTemplate0" runat="server">
10.                                    <Content>
11.                                        <div class="booked">{DayOfMonth}</div>
12.                                    </Content>
13.                                </telerik:DayTemplate>
14.                            </CalendarDayTemplates>
15.                        </telerik:RadCalendar>
16.                        </div>
17.                        <div style="float: left; width: 50%;">
18.                            Til Dato:
19.                        <telerik:RadCalendar ID="ToDate" RangeMinDate="<%# DateTime.Today %>" runat="server" OnDayRender="Calendar_DayRender" Enabled="False" ShowOtherMonthsDays="False"
20.                            EnableAriaSupport="True" EnableShadows="True" AutoPostBack="True" EnableMultiSelect="False" >
21.                            <CalendarDayTemplates>
22.                                <telerik:DayTemplate ID="BlockedTemplate1" runat="server">
23.                                    <Content>
24.                                        <div class="blocked">{DayOfMonth}</div>
25.                                    </Content>
26.                                </telerik:DayTemplate>
27.                                <telerik:DayTemplate ID="BookedTemplate1" runat="server">
28.                                    <Content>
29.                                        <div class="booked">{DayOfMonth}</div>
30.                                    </Content>
31.                                </telerik:DayTemplate>
32.                            </CalendarDayTemplates>
33.                        </telerik:RadCalendar>
34.                        </div>

01.private IQueryable<CabinWeb.OpenAccess.Booking> _bookings;
02.private IQueryable<Blocked> _blockings;
03.
04.protected void Page_Load(object sender, EventArgs e)
05.{
06.    InitCalendar();
07.    if (_blockings == null && _bookings == null) return;
08.    var cal = FromDate;
09.    cal.SpecialDays.Clear();
10.    cal.SpecialDays.AddRange(BlockedDates(CalendarType.FromDate));
11.    cal.SpecialDays.AddRange(BookedDates(CalendarType.FromDate));
12.    var cal2 = ToDate;
13.    cal2.SpecialDays.Clear();
14.    cal2.SpecialDays.AddRange(BlockedDates(CalendarType.ToDate));
15.    cal2.SpecialDays.AddRange(BookedDates(CalendarType.ToDate));
16.}
17.
18.private void InitCalendar()
19.{
20.    var cabinId = ddlCabin.SelectedValue.ToInt(-1);
21.    var cabinController = new CabinController(Session["company_id"].ToString().ToInt());
22.    var cabin = cabinController.GetById(cabinId);
23.    if (cabin != null)
24.    {
25.        FromDate.Enabled = true;
26.        FromDate.RangeMinDate = DateTime.Today.AddDays(-14);
27.        FromDate.RangeMaxDate = DateTime.Today.AddDays(100);
28.        _bookings =
29.            cabin.Bookings.Where(
30.                b =>
31.                    b.To_date > FromDate.RangeMinDate && b.From_date < FromDate.RangeMaxDate &&
32.                    (b.Cancelled == null || (b.Cancelled != null && b.Cancelled.Value == 0))).AsQueryable();
33.        _blockings =
34.            cabin.Blockeds.Where(
35.                b => b.To_date > FromDate.RangeMinDate && b.From_date < FromDate.RangeMaxDate && b.Active == true).AsQueryable();
36.    }
37.}
38.
39.private RadCalendarDay[] BlockedDates(CalendarType calendar)
40.{
41.    var version = (calendar == CalendarType.FromDate) ? 0 : 1;
42.    var template = "BlockedTemplate" + version;
43.
44.    var cal = new List<RadCalendarDay>();
45.    foreach (var blocked in _blockings)
46.    {
47.        if (blocked.From_date == null || blocked.To_date == null) continue;
48.        var startDate = (calendar == CalendarType.ToDate) ? blocked.From_date.Value.AddDays(1) : blocked.From_date.Value;
49.        var endDate = (calendar == CalendarType.FromDate) ? blocked.To_date.Value.AddDays(-1) : blocked.To_date.Value;
50.        for (var day = startDate; day <= endDate; day = day.AddDays(1))
51.        {
52.            cal.Add(FormatDate(day, template));
53.        }
54.    }
55.    var days = cal.ToArray();
56.    return days;
57.
58.}
59.
60.private RadCalendarDay[] BookedDates(CalendarType calendar)
61.{
62.    var version = (calendar == CalendarType.FromDate) ? 0 : 1;
63.    var template = "BookedTemplate" + version;
64.    var cal = new List<RadCalendarDay>();
65.    foreach (var booking in _bookings)
66.    {
67.        if (booking.From_date == null || booking.To_date == null) continue;
68.        var startDate = (calendar == CalendarType.ToDate) ? booking.From_date.Value.AddDays(1) : booking.From_date.Value;
69.        var endDate = (calendar == CalendarType.ToDate) ? booking.To_date.Value.AddDays(1) : booking.To_date.Value;
70.        for (var day = startDate; day < endDate; day = day.AddDays(1))
71.        {
72.            cal.Add(FormatDate(day, template));
73.        }
74.    }
75.    var days = cal.ToArray();
76.    return days;
77.}
78.
79.private RadCalendarDay FormatDate(DateTime day, string template)
80.{
81.    var calDay = new RadCalendarDay { Date = day, IsSelectable = false, IsDisabled = true };
82.    calDay.TemplateID = template;
83.    return calDay;
84.}

01.       protected void RadCalendar_SelectionChanged(object sender, SelectedDatesEventArgs e)
02.        {
03.            FromDate.Enabled = true;
04.            var startDate = FromDate.SelectedDate.AddDays(1);
05.            ToDate.RangeMinDate = startDate;
06.            ToDate.RangeMaxDate = FirstUnavailableDate(startDate);
07.        }
08.
09.        private DateTime FirstUnavailableDate(DateTime startDate)
10.        {
11.            var defaultDate = startDate.AddDays(100);
12.            if (_bookings == null && _blockings == null)
13.                return defaultDate;
14.            if (!_bookings.Any() && !_blockings.Any())
15.                return defaultDate;
16.
17.            var futureBookings = _bookings.Where(b => b.From_date >= startDate);
18.            var futureBlockings = _blockings.Where(b => b.From_date >= startDate);
19.            var firstBooking = futureBookings.Any() ? futureBookings.Min(b => b.From_date.Value) : defaultDate;
20.            var firstBlocking = futureBlockings.Any()? futureBlockings.Min(b => b.From_date.Value) : defaultDate;
21.            var result = firstBooking.CompareTo(firstBlocking);
22.            return result <= 0 ? firstBooking : firstBlocking;
23.        }
24.
25.        protected void CabinSelectedIndexChanged(object sender, EventArgs e)
26.        {
27.            FromDate.Enabled = true;
28.            ToDate.Enabled = false;
29.            FromDate.SelectedDates.Clear();
30.            ToDate.SelectedDates.Clear();
31.
32.        }
33.
34.        protected void Calendar_DayRender(object sender, DayRenderEventArgs e)
35.        {
36.            e.Cell.Text = e.Cell.Text.Replace("{DayOfMonth}", e.Day.Date.Day.ToString());
37.        }
38.    }
39.
40.    enum CalendarType
41.{
42.    FromDate, ToDate
43.}

Thanks,

Terje K.

[Shinu]

Hi Terje,

The posted code is not readable for me. Can you please post the code again for further help.

Thanks,
Shinu.

[Maria Ilieva]

Hi Terje,

Please use the code formatting tool when submitting code snippets in your tickets so that we could easily read it on our end and do our best to provide proper solution.

Regards,
Maria Ilieva
Telerik

 

 

[Terje]

I did use the formatting tool. The problem is probably to do with setting the height parameter...

Im on holiday now, so i dont have access to the code. I Will repost it without height parameter when i get back next week. 

And to telerik: typing on the forum with a mobile phone is typing blind. Cant See what I write. Cant See what others have written while answering...

[Maria Ilieva]

Hi Terje,

I will forward your report for the ticketing system to the corresponding team responsible for our site, so that they could further test the described case and fix the problem as soon as possible.

As for your code, as soon as we have it in some readable format we will do our best to isolate the root cause of the issue and get back to you with a solution.

Regards,
Maria Ilieva
Telerik

 

 

[Terje]

Here is my code. I have stripped non-essential code for simplicity:

front-end:

<style>
    .booked {
        background-color: darkred;
        color: white;
        font-style: italic;
    }

    .blocked {
        background-color: darkorange;
        color: white;
        font-style: italic;
    }
</style>
<div style="float: left; width: 50%;">
    Fra Dato:
<telerik:RadCalendar ID="FromDate" RangeMinDate="<%# DateTime.Today %>" OnDayRender="Calendar_DayRender" runat="server" SelectedDate="<%# DateTime.Today %>" Enabled="False"
    EnableAriaSupport="True" EnableShadows="True" AutoPostBack="True" EnableMultiSelect="False" OnSelectionChanged="RadCalendar_SelectionChanged" ShowOtherMonthsDays="False">
    <CalendarDayTemplates>
        <telerik:DayTemplate ID="BlockedTemplate0" runat="server">
            <Content>
                <div class="blocked">{DayOfMonth}</div>
            </Content>
        </telerik:DayTemplate>
        <telerik:DayTemplate ID="BookedTemplate0" runat="server">
            <Content>
                <div class="booked">{DayOfMonth}</div>
            </Content>
        </telerik:DayTemplate>
    </CalendarDayTemplates>
</telerik:RadCalendar>
</div>
<div style="float: left; width: 50%;">
    Til Dato:
<telerik:RadCalendar ID="ToDate" RangeMinDate="<%# DateTime.Today %>" runat="server" OnDayRender="Calendar_DayRender" Enabled="False" ShowOtherMonthsDays="False"
    EnableAriaSupport="True" EnableShadows="True" AutoPostBack="True" EnableMultiSelect="False" >
    <CalendarDayTemplates>
        <telerik:DayTemplate ID="BlockedTemplate1" runat="server">
            <Content>
                <div style="background-color: darkorange;color: white;font-style: italic;">{DayOfMonth}</div>
            </Content>
        </telerik:DayTemplate>
        <telerik:DayTemplate ID="BookedTemplate1" runat="server">
            <Content>
                <div style="background-color: darkred;color: white;font-style: italic;">{DayOfMonth}</div>
            </Content>
        </telerik:DayTemplate>
    </CalendarDayTemplates>
</telerik:RadCalendar>
</div>

code-behind:

    public partial class AdminBookingNew : BasePage
    {
        private IQueryable<CabinWeb.OpenAccess.Booking> _bookings;
        private IQueryable<Blocked> _blockings;

        protected void Page_Load(object sender, EventArgs e)
        {
            InitCalendar();
            if (_blockings == null && _bookings == null) return;
            var cal = FromDate;
            cal.SpecialDays.Clear();
            cal.SpecialDays.AddRange(BlockedDates(CalendarType.FromDate));
            cal.SpecialDays.AddRange(BookedDates(CalendarType.FromDate));
            var cal2 = ToDate;
            cal2.SpecialDays.Clear();
            cal2.SpecialDays.AddRange(BlockedDates(CalendarType.ToDate));
            cal2.SpecialDays.AddRange(BookedDates(CalendarType.ToDate));
        }


        private void InitCalendar()
        {
            var cabinId = ddlCabin.SelectedValue.ToInt(-1);
            var cabinController = new CabinController(Session["company_id"].ToString().ToInt());
            var cabin = cabinController.GetById(cabinId);
            if (cabin != null)
            {
                FromDate.Enabled = true;
                FromDate.RangeMinDate = DateTime.Today.AddDays(-14);
                FromDate.RangeMaxDate = DateTime.Today.AddDays(100);
                _bookings =
                    cabin.Bookings.Where(
                        b =>
                            b.To_date > FromDate.RangeMinDate && b.From_date < FromDate.RangeMaxDate &&
                            (b.Cancelled == null || (b.Cancelled != null && b.Cancelled.Value == 0))).AsQueryable();
                _blockings =
                    cabin.Blockeds.Where(
                        b => b.To_date > FromDate.RangeMinDate && b.From_date < FromDate.RangeMaxDate && b.Active == true).AsQueryable();
            }
        }


        private RadCalendarDay[] BlockedDates(CalendarType calendar)
        {
            var version = (calendar == CalendarType.FromDate) ? 0 : 1;
            var template = "BlockedTemplate" + version;

            var cal = new List<RadCalendarDay>();
            foreach (var blocked in _blockings)
            {
                if (blocked.From_date == null || blocked.To_date == null) continue;
                var startDate = (calendar == CalendarType.ToDate) ? blocked.From_date.Value.AddDays(1) : blocked.From_date.Value;
                var endDate = (calendar == CalendarType.FromDate) ? blocked.To_date.Value.AddDays(-1) : blocked.To_date.Value;
                for (var day = startDate; day <= endDate; day = day.AddDays(1))
                {
                    cal.Add(FormatDate(day, template));
                }
            }
            var days = cal.ToArray();
            return days;

        }

        private RadCalendarDay[] BookedDates(CalendarType calendar)
        {
            var version = (calendar == CalendarType.FromDate) ? 0 : 1;
            var template = "BookedTemplate" + version;
            var cal = new List<RadCalendarDay>();
            foreach (var booking in _bookings)
            {
                if (booking.From_date == null || booking.To_date == null) continue;
                var startDate = (calendar == CalendarType.ToDate) ? booking.From_date.Value.AddDays(1) : booking.From_date.Value;
                var endDate = (calendar == CalendarType.ToDate) ? booking.To_date.Value.AddDays(1) : booking.To_date.Value;
                for (var day = startDate; day < endDate; day = day.AddDays(1))
                {
                    cal.Add(FormatDate(day, template));
                }
            }
            var days = cal.ToArray();
            return days;
        }

        private RadCalendarDay FormatDate(DateTime day, string template)
        {
            var calDay = new RadCalendarDay { Date = day, IsSelectable = false, IsDisabled = true };
            calDay.TemplateID = template;
            return calDay;
        }

        protected void RadCalendar_SelectionChanged(object sender, SelectedDatesEventArgs e)
        {
            ToDate.Enabled = true;
            var startDate = FromDate.SelectedDate.AddDays(1);
            ToDate.RangeMinDate = startDate;
            ToDate.RangeMaxDate = FirstUnavailableDate(startDate);
        }

        private DateTime FirstUnavailableDate(DateTime startDate)
        {
            var defaultDate = startDate.AddDays(100);
            if (_bookings == null && _blockings == null)
                return defaultDate;
            if (!_bookings.Any() && !_blockings.Any())
                return defaultDate;

            var futureBookings = _bookings.Where(b => b.From_date >= startDate);
            var futureBlockings = _blockings.Where(b => b.From_date >= startDate);
            var firstBooking = futureBookings.Any() ? futureBookings.Min(b => b.From_date.Value) : defaultDate;
            var firstBlocking = futureBlockings.Any() ? futureBlockings.Min(b => b.From_date.Value) : defaultDate;
            var result = firstBooking.CompareTo(firstBlocking);
            return result <= 0 ? firstBooking : firstBlocking;
        }

        protected void CabinSelectedIndexChanged(object sender, EventArgs e)
        {
            FromDate.Enabled = true;
            ToDate.Enabled = false;
            FromDate.SelectedDates.Clear();
            ToDate.SelectedDates.Clear();

        }

        protected void Calendar_DayRender(object sender, DayRenderEventArgs e)
        {
            e.Cell.Text = e.Cell.Text.Replace("{DayOfMonth}", e.Day.Date.Day.ToString());
        }
    }

    enum CalendarType
    {
        FromDate, ToDate
    }
}

[Shinu]

Hi Terje,

In order to style the disabled dates please try the below CSS which works fine at my end.

CSS:

.rcDisabled
{
    background-color: darkorange;
    color: white;
    font-style: italic;
}

Thanks,
Shinu.

[Terje]

Hi again.

Everything seems to work fine in the first calendar (from-date), but as soon as I click a date on the first calendar, all formatting disappears from the second calendar (to-date). Even the formatting from your suggestion disappears.

I have attached screenshots of how it looks on init (oninit.png) and after dateselection in first calendar (onclick.png)

[Shinu]

Hi Terje,

Unfortunately I couldn't replicate the issue at my end. Please have a look into the sample code snippet which works fine at my end.

ASPX:

<telerik:RadCalendar ID="FromDate" OnDayRender="Calendar_DayRender" runat="server"  EnableAriaSupport="True" EnableShadows="True" AutoPostBack="True" EnableMultiSelect="False" ShowOtherMonthsDays="False" RangeMinDate="<%# DateTime.Today %>" SelectedDate="<%# DateTime.Today %>">
    <CalendarDayTemplates>
        <telerik:DayTemplate ID="BlockedTemplate0" runat="server">
            <Content>
                <div>
                    {DayOfMonth}
                </div>
            </Content>
        </telerik:DayTemplate>
    </CalendarDayTemplates>
</telerik:RadCalendar>
<telerik:RadCalendar ID="ToDate"OnDayRender="Calendar_DayRender" runat="server"EnableAriaSupport="True" EnableShadows="True" AutoPostBack="True" EnableMultiSelect="False" ShowOtherMonthsDays="False"  RangeMinDate="<%# DateTime.Today %>"  SelectedDate="<%# DateTime.Today %>"  >
    <CalendarDayTemplates>
        <telerik:DayTemplate ID="BookedTemplate0" runat="server">
            <Content>
                <div>
                    {DayOfMonth}
                </div>
            </Content>
        </telerik:DayTemplate>
    </CalendarDayTemplates>
</telerik:RadCalendar>

C#:

protected void Page_Load(object sender, EventArgs e)
{
    var cal = FromDate;
    cal.SpecialDays.Clear();
    cal.SpecialDays.AddRange(BlockedDates(CalendarType.FromDate));
    var cal1 = ToDate;
    cal1.SpecialDays.Clear();
    cal1.SpecialDays.AddRange(BookedDates(CalendarType.ToDate));
}
private RadCalendarDay[] BlockedDates(CalendarType calendar)
{
    var version = (calendar == CalendarType.FromDate) ? 0 : 1;
    var template = "BlockedTemplate"+version;
    var cal = new List<RadCalendarDay>();
    var i = 0;
    var startDate = (calendar == CalendarType.ToDate) ? DateTime.Now.AddDays(-1) : DateTime.Now.AddDays(-2);
    var endDate = (calendar == CalendarType.FromDate) ? DateTime.Now.AddDays(-3) : DateTime.Now.AddDays(-4);
    for (var day = startDate; i<3; day = day.AddDays(1))
    {
        cal.Add(FormatDate(day, template));
        i++;
    }
    var days = cal.ToArray();
    return days;
}
private RadCalendarDay[] BookedDates(CalendarType calendar)
{
    var version = (calendar == CalendarType.ToDate) ? 0 : 1;
    var template = "BookedTemplate"+version;
    var cal = new List<RadCalendarDay>();
    var i = 0;
    var startDate = (calendar == CalendarType.ToDate) ? DateTime.Now.AddDays(-1) : DateTime.Now.AddDays(-2);
    var endDate = (calendar == CalendarType.FromDate) ? DateTime.Now.AddDays(-3) : DateTime.Now.AddDays(-4);
    for (var day = startDate; i < 3; day = day.AddDays(1))
    {
        cal.Add(FormatDate(day, template));
        i++;
    }
    var days = cal.ToArray();
    return days;
}
private RadCalendarDay FormatDate(DateTime day, string template)
{
    var calDay = new RadCalendarDay { Date = day, IsSelectable = false, IsDisabled = true };
    calDay.TemplateID = template;
    return calDay;
}
protected void Calendar_DayRender(object sender, Telerik.Web.UI.Calendar.DayRenderEventArgs e)
{
   e.Cell.Text = e.Cell.Text.Replace("{DayOfMonth}", e.Day.Date.Day.ToString());
}
enum CalendarType
{
    FromDate, ToDate
}

CSS:

.rcDisabled
{
    background-color: darkorange;
    color: white;
    font-style: italic;
}

Thanks,
Shinu.