RadCalendar WeekNumber

[Rob Venable]

Hi,
Is it possible to return the WeekNumber of a RadCalendar on PostBack?
I need to pass the weeknumber (and probably the year also) to my function so that I can return sales for this week.

Is this possible?

Thanks

[Princy]

Hi Rob,

Here is the code snippet to retrieve the WeekNumber of selected date of Calendar.

CS:

    protected void Button1_Click(object sender, EventArgs e)
    {
        DateTime dt = (DateTime)RadCalendar1.SelectedDate;
        int number = GetWeekNumber(dt);  // Week number
        int year = dt.Year;   // Year
    }
    public int GetWeekNumber(DateTime dtDate)
    {
        CultureInfo ciCurr = CultureInfo.CurrentCulture;
        int weekNum = ciCurr.Calendar.GetWeekOfYear(dtDate, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);
        return weekNum+1;
    }

Regards,
Princy.

[Rob Venable]

Thanks Princy. That's exactly what I needed.

[@CC]

Hello:

RadDatePicker with WeekNo showing:

<telerik:RadDatePicker ID="uxDatePicker" runat="server" AutoPostBack="true" OnSelectedDateChanged=OnSelectedDateChanged Skin="Windows7" Culture="English (United States)" >
   <Calendar ID="Calendar1" runat="server" ShowColumnHeaders="true" ShowRowHeaders="true" >
      <ClientEvents OnLoad="AddEvent" />
   </Calendar>
</telerik:RadDatePicker>

Based on the above code by princy, the week no does not match with the radDatePicker's week number for say '12/28/2010' the function returns 53 whereas radDatePicker says 1. Any suggestions?

[Vasil]

Hi,

Actually 12/28/2010 is in 52 week, in both US and ISO standards. So both 51 and 1 are wrong.

Try the following code-snippets:

Aspx:

<telerik:RadDatePicker ID="RadDatePicker1" AutoPostBack="true" runat="server" OnSelectedDateChanged="RadDatePicker1_SelectedDateChanged">
    <Calendar runat="server">
    </Calendar>
    <DateInput runat="server" DisplayDateFormat="M/d/yyyy" DateFormat="M/d/yyyy" AutoPostBack="True">
    </DateInput>
    <DatePopupButton ImageUrl="" HoverImageUrl=""></DatePopupButton>
</telerik:RadDatePicker>
<label id="Label1" runat="server">
</label>

Cs:

protected void Page_Load(object sender, EventArgs e)
{
    CultureInfo c = new CultureInfo("en-US");
    c.DateTimeFormat.CalendarWeekRule = CalendarWeekRule.FirstFourDayWeek;
    c.DateTimeFormat.FirstDayOfWeek = DayOfWeek.Monday;
    RadDatePicker1.Calendar.CultureInfo = c;
}

protected void RadDatePicker1_SelectedDateChanged(object sender, Telerik.Web.UI.Calendar.SelectedDateChangedEventArgs e)
{
    DateTime dt = (DateTime)RadDatePicker1.SelectedDate;
    CultureInfo c = RadDatePicker1.Calendar.CultureInfo;
    int number = c.Calendar.GetWeekOfYear(dt, c.DateTimeFormat.CalendarWeekRule, c.DateTimeFormat.FirstDayOfWeek);
    Label1.InnerText = number.ToString();
}

This should get you the right day when you use GetWeekOfYear.

Be aware that you still will have divergence in some cases.
For example:
    12/31/2012 is 53 week by the ISO standard.
    01/01/2013 is 1 week by the ISO standard.
Both this days, however are in the same week. In calendar week column, you can see only one number. It can not show 53 and 1 at the same time. And it shows 1.

All the best,
Vasil
the Telerik team