The Coolest DHTML Calendar，这是一个在GPL下发布的JS日历程序，具有极高的可配置性，包括外观样式、显示格式、显示内容等等。默认程序是只提供日期选择的，需要设置几个showtime参数才能显示时间选择。下载的程序包(zip)里面已经有详细的说明文档和例子.
这个控件的aspnet 1.1版本的代码在我的donews blog上,代码可以自由修改发布.

using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;
using System.IO;
using System.Text;
using System.Globalization;
namespace DotnetClubPortal.WebControls
{
 /// <summary>
 /// An ASP.NET Server Control that wraps mishoo's javascript calendar
 /// ([url]http://www.dynarch.com/projects/calendar/[/url]).
 /// </summary>
 [DefaultProperty("Text"), ToolboxData("<{0}:Calendar runat=server></{0}:Calendar>")]
 [ValidationProperty("Text")]
 public class Calendar : CompositeControl, INamingContainer
 {
  private TextBox _dateTextBox;
  private Image _calendarImage;
  #region properties
 
  [Bindable(true), Category("Appearance"), DefaultValue("")]
  public string Text
  {
   get
   {
    EnsureChildControls();
    return this._dateTextBox.Text;
   }
   set
   {
    EnsureChildControls();
    this._dateTextBox.Text = value;
   }
  }
  [Bindable(true), Category("Appearance"), DefaultValue(CalendarTheme.system)]
  public CalendarTheme Theme
  {
   get { return (ViewState["Theme"] != null ? (CalendarTheme)ViewState["Theme"] : CalendarTheme.system); }
   set { ViewState["Theme"] = value; } 
  }
  [Bindable(true), Category("Behavior"), DefaultValue(CalendarLanguage.en)]
  public CalendarLanguage Language
  {
   get { return (ViewState["Language"] != null ? (CalendarLanguage)ViewState["Language"] : CalendarLanguage.en); }
   set { ViewState["Language"] = value; }  
  }
  [Bindable(true), Category("Behavior"), DefaultValue("~/Support/JsCalendar")]
  public string SupportDir
  {
   get { return (ViewState["SupportDir"] != null ? (string)ViewState["SupportDir"] : ""); }
   set { ViewState["SupportDir"] = value; }  
  }
  [Bindable(true), Category("Behavior"), DefaultValue(false)]
  public bool DisplayTime
  {
   get { return (ViewState["DisplayTime"] != null ? (bool)ViewState["DisplayTime"] : false); }
   set { ViewState["DisplayTime"] = value; }  
  }
  [Browsable(false), Bindable(false)]
  public string DateFormat
  {
   get { return (ViewState["DateFormat"] != null ? (string)ViewState["DateFormat"] : ""); }
   set { ViewState["DateFormat"] = value; }  
  }
  [Browsable(false), Bindable(false)]
  public string TimeFormat
  {
   get { return (ViewState["TimeFormat"] != null ? (string)ViewState["TimeFormat"] : ""); }
   set { ViewState["TimeFormat"] = value; }  
  }
  [Bindable(true), Category("Behavior")]
  public DateTime SelectedDate
  {
   get
   {
    EnsureChildControls();
    if (this.Text.Length > 0)
    {
     try
     {
      return DateTime.Parse(this.Text);
     }
     catch (FormatException ex)
     {
      System.Diagnostics.Trace.WriteLine("Invalid datetime: " + this._dateTextBox.Text + " " + ex.Message, this.GetType().FullName);
      return DateTime.MinValue;
     }
    }
    else
    {
     return DateTime.MinValue;
    }
   }
   set
   {
    EnsureChildControls();
    this.Text = value.ToShortDateString();
    if (this.DisplayTime)
    {
     this.Text += " " + value.ToShortTimeString();
    }
   }
  }
  public override ControlCollection Controls
  {
   get
   {
    EnsureChildControls();
    return base.Controls;
   }
  }
  
  [TypeConverter(typeof(UnitConverter))]
  public override Unit Width
  {
   get
   {
    EnsureChildControls();
    return base.Width;
   }
   set
   {
    EnsureChildControls();
    base.Width = value;
    this._dateTextBox.Width = Unit.Pixel((int)value.Value - 24);
   }
  }
 
  #endregion
  public event System.EventHandler DateChanged;
  protected virtual void OnDateChanged(object sender)
  {
   if (DateChanged != null)
   {
    DateChanged(sender, System.EventArgs.Empty);
   }
  }
  public Calendar()
  {
   // Set defaults
   this.Theme = CalendarTheme.system;
   this.SupportDir = "~/Support/JsCalendar";
   this.DisplayTime = false;
   this.DateFormat = ConvertDateFormat(CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern);
   this.TimeFormat = ConvertTimeFormat(CultureInfo.CurrentCulture.DateTimeFormat.ShortTimePattern);
   SetLanguage();
  }
  protected override void CreateChildControls()
  {
   this._dateTextBox = new TextBox();
   this._calendarImage = new Image();
   this._dateTextBox.EnableViewState = true;
   this._dateTextBox.ID = "dateTextBox";
   this._dateTextBox.TextChanged += new EventHandler(DateTextBox_TextChanged);
   this._calendarImage.EnableViewState = false;
   this._calendarImage.ID = "trigger";
   this._calendarImage.ImageUrl = GetClientFileUrl("cal.gif");
   this._calendarImage.Attributes["align"] = "top";
   this._calendarImage.Attributes["hspace"] = "4";
   Controls.Add(this._dateTextBox);
   Controls.Add(this._calendarImage);
  }
  /// <summary>
  /// Render this control to the output parameter specified.
  /// </summary>
  /// <param name="output"> The HTML writer to write out to </param>
  protected override void Render(HtmlTextWriter output)
  {
   if (this.Site != null && this.Site.DesignMode)
   {
    this._dateTextBox.RenderControl(output);
    output.Write("[" + this.ID + "]");
   }
   else
   {
    base.Render(output);
   }
  }
  protected override void OnPreRender(EventArgs e)
  {
   base.OnPreRender (e);
   string themeCss = GetClientCssImport(String.Format("calendar-{0}.css", this.Theme.ToString().Replace("_", "-")));
   Page.ClientScript.RegisterClientScriptBlock(themeCss.GetType(),"calendarcss", themeCss);
   string calendarScripts = "";
   calendarScripts += GetClientScriptInclude("calendar.js",this.Language);
   calendarScripts += GetClientScriptInclude("calendar-setup.js",this.Language);
   string languageFile = String.Format("lang/calendar-{0}.js", this.Language.ToString());
   calendarScripts += GetClientScriptInclude(languageFile,this.Language);
            Page.ClientScript.RegisterClientScriptBlock(calendarScripts.GetType(), "calendarscripts", calendarScripts);
   string setupScript = GetCalendarSetupScript(this._dateTextBox.ClientID, GetFormatString(), this.ClientID);
            Page.ClientScript.RegisterStartupScript(setupScript.GetType(), this.ClientID + "script", setupScript);
  }
  private void SetLanguage()
  {
   string currentLanguage = CultureInfo.CurrentCulture.TwoLetterISOLanguageName;
   try
   {
    CalendarLanguage cl = (CalendarLanguage)Enum.Parse(typeof(CalendarLanguage), currentLanguage);
    this.Language = cl;
   }
   catch
   {
    // Default is 'en'
    this.Language = CalendarLanguage.en;
   }
  }
  private string GetClientFileUrl(string fileName)
  {
   return ResolveUrl(this.SupportDir + "/" + fileName);
  }
  private string GetClientScriptInclude(string scriptFile,CalendarLanguage language)
  {
   string strScript = string.Empty;
   if(language == CalendarLanguage.zh)
   {
    strScript = "<script language=\"JavaScript\" src=\"" +                   
     GetClientFileUrl(scriptFile) + "\" charset=\"gb2312\"></script>\n";
   }
   else
   {
    strScript = "<script language=\"JavaScript\" src=\"" +
     GetClientFileUrl(scriptFile) + "\"></script>\n";
   }
   return strScript;
  }
  private string GetClientCssImport(string fileName)
  {
   return "<style type=\"text/css\">@import url(" + GetClientFileUrl(fileName) + ");</style>";
  }
  private string GetCalendarSetupScript(string inputField, string format, string trigger)
  {
   StringBuilder sb = new StringBuilder();
   sb.Append("<script type=\"text/javascript\">Calendar.setup( { inputField : \"");
   sb.Append(inputField);
   sb.Append("\", ifFormat : \"");
   sb.Append(format);
   sb.Append("\", button : \"");
   sb.Append(trigger);
   sb.Append("\", showsTime : ");
   sb.Append(this.DisplayTime.ToString().ToLower());
   sb.Append(" } ); </script>");
   return sb.ToString();
  }
  public string GetFormatString()
  {
   if (this.DisplayTime)
   {
    return this.DateFormat + " " + this.TimeFormat;
   }
   else
   {
    return this.DateFormat;
   }
  }
  private void DateTextBox_TextChanged(object sender, EventArgs e)
  {
   OnDateChanged(sender);
  }
  private string ConvertDateFormat(string shortDateFormat)
  {
   string tempFormat = shortDateFormat.Replace("yyyy", "%Y");
   tempFormat = tempFormat.Replace("M", "%m");
   tempFormat = tempFormat.Replace("d", "%d");
   return tempFormat;
  }
  private string ConvertTimeFormat(string shortTimeFormat)
  {
   string tempFormat = shortTimeFormat.Replace("H", "%H");
   tempFormat = tempFormat.Replace("mm", "%M");
   tempFormat = tempFormat.Replace("h", "%I");
   tempFormat = tempFormat.Replace("tt", "%p");
   return tempFormat;
  }
 }
 public enum CalendarTheme
 {
  blue,
  blue2,
  brown,
  green,
  win2k_1,
  win2k_2,
  win2k_cold_1,
  win2k_cold_2,
  system
 }
 public enum CalendarLanguage
 {
  af,
  br,
  ca,
  da,
  de,
  du,
  el,
  en,
  es,
  fi,
  fr,
  hr,
  hu,
  it,
  jp,
  ko,
  lt,
  nl,
  no,
  pl,
  pt,
  ro,
  ru,
  sl,
  si,
  sk,
  sp,
  sv,
  tr,
  zh
 }
}

代码和示例下载地址: demo
自由、创新、研究、探索……