The MultiSelectionCalendar control is a variation of the Calendar Control  that allows multiple selections. Use it when you need to store a list of dates. It has most of the same 200+ properties from the Calendar control including support for the SpecialDates Control  with its powerful formatting features and Multiple Month View.

Product Features

• There are several selection modes:
  • Individual dates. When turned off, you can prevent selecting single dates. This lets you use the week, month, and day of week features exclusively.
  • By week
  • By month
  • By day of the week
  • Range. Keeps a contiguious selection between the earliest and latest dates.
  • Use the SHIFT key to extend the selection from the last cell selected.
   Deep Dive on Selection Modes   
• You can limit the number of dates selection and show an alert when that limit is exceeded.
• The Current Date Label can show the number of dates selected or the start and end dates.
  
   Deep Dive on the Current Date Label   
• One challenge users face with most multiple selection calendars is how to interact with it. This control introduces the Message Center, an interactive help section at the bottom of the control.
  
   Deep Dive on the Message Center   

Demos

August 2020 Sun Mon Tue Wed Thu Fri Sat 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 Today   Clear   Show   Previous Month   Next Month   Previous Year   Next Year	August 2020 Sun Mon Tue Wed Thu Fri Sat 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 Click on dates to toggle their selection.	August 2020 Sun Mon Tue Wed Thu Fri Sat 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 Click on dates to toggle their selection.
The default without the Message Center.	Adds select by week.	All selection modes available. Also imposes a limit of no more than 40 days selected.
August 2020 - September 2020 August 2020   Sun Mon Tue Wed Thu Fri Sat 31 26 27 28 29 30 31 1 32 2 3 4 5 6 7 8 33 9 10 11 12 13 14 15 34 16 17 18 19 20 21 22 35 23 24 25 26 27 28 29 36 30 31 1 2 3 4 5 September 2020   Sun Mon Tue Wed Thu Fri Sat 36 30 31 1 2 3 4 5 37 6 7 8 9 10 11 12 38 13 14 15 16 17 18 19 39 20 21 22 23 24 25 26 40 27 28 29 30 1 2 3 41 4 5 6 7 8 9 10 Today Clear Show Click on dates to toggle their selection.
User must select a range. A few formatting options have been added.

The ASP.NET markup for these demos:

<des:MultiSelectionCalendar id="MultiSelectionCalendar1" runat="server" >
   <MessageCenter Activate="false" />
</des:MultiSelectionCalendar>
<des:MultiSelectionCalendar id="MultiSelectionCalendar2" runat=server SelectWeeks="True"></des:MultiSelectionCalendar>
<des:MultiSelectionCalendar id="MultiSelectionCalendar3" runat="server" 
   SelectWeeks="True" SelectMonth="True" SelectDOW="True" MaximumSelectedDates="40">
   <CurrentDateLabels ShowField="RecommendedRow" />
</des:MultiSelectionCalendar>
<des:MultiSelectionCalendar id="MultiSelectionCalendar4" runat="server" 
   RangeMode="True" AutoFormatYearChangeButtonPositions="Recommended"
   MultiMonthColumnCount="2" ShowWeekNumbers="True" >
   <TodayCommand ShowField="FooterRow1" RegionInRow="Right" />
   <ClearCommand ShowField="FooterRow1" RegionInRow="Right" />
   <ShowSelectionCommand ShowField="FooterRow1" RegionInRow="Right" />
   <CurrentDateLabels ShowField="FooterRow1" RegionInRow="Left" DateFormatWithMultipleSelections="AbbreviatedNoYear" />
</des:MultiSelectionCalendar>