Hui’s Calendar Tool (as Borrowed from Chandoo)

In January a friend asked me to assist with a small Excel assignment.

Her company wanted to add a Calendar control to a worksheet so that people could interactively select a date. I have never understood why people like this as nothing is quicker than typing a date as 7/4/14 and letting excel sort it out. But hey, that’s what the client wants.

The issue was that it had to work in every version of Excel from Excel 2002/XP to Excel 2013.

As anybody who has used the Calendar controls in Excel VBA Knows, they rarely work between versions and often require VBA references to be added/changed and DLL’s downloaded to make them work.

This model had to be able to be opened across all the Excel versions from Excel 2002/XP to Excel 13 and even transferred from one version to another regularly.

After struggling with the concept a while I threw away the Calendar Control idea and decided to plagiarise Chandoo’s 2014 Calendar.

Hui’s Chandoo’s Calendar Tool

Every year Chandoo releases a Yearly Calendar as a small gift to his readers. The 2014 calendar is available here.

It has all the facilities of a calendar using simple worksheet functions and Named Formula, and it doesn’t use VBA.

So, why not add a bit of generic VBA and use this as a Calendar selection tool?

The Process

Chandoo’s 2014 Calendar was stripped down to its absolute basic being 2 worksheets and a number of named Formulas which controlled the calculations.

The idea was to:

1. Let the user to Select a cell, where they want to enter a date, It can be any cell on any worksheet.
2. Press a Calendar Button or or Double Click on the cell and be taken to a Calendar.
3. Select a date in the Calendar.
4. Have a level of validation/acceptance of certain dates and rejection of other dates.
5. Be taken back to the original worksheet and have the date placed into the original cell.

The calendar should pop up and be hidden by VBA code and shouldn’t require the user to know how to do that.

The Calendar had to have a level of user ability to modify the selection criteria and obviously the active year.

The calendar shouldn’t be reliant on any Addins, DLL’s or other external files.

Lets have a look at the components.

The Components

The following description and images use a sample file which you can Download here.

The File is compatible with all PC Excel versions but your screens may look slightly different in different versions, mostly colors are rendered slightly differently.

If you use a Mac Excel version, please let us know how this goes?

The Interface

The Interface is simple, You select a cell where you want to insert a date and press the Calendar Button or Double Click the cell:

The calendar Button uses some simple VBA to store the names of the worksheet and cell where the cursor was when the button was pressed and then opens the Calendar sheet by un-hiding it (making it visible) as per below:

The above image shows the calendar.

This user wanted to only allow Fridays or Saturdays to be selected and so they are manually colored Yellow.

If you select any non-yellow cell – Nothing happens

If you select any yellow cell – That date is returned to your original location

Click on the Year and change it to another value to change years

Selecting the Close button closes the calendar and returns you to your original location with no changes.

You can change the Dates that are allowable to be selectable by either changing the VBA or Selecting Multiple cells and coloring as appropriate.

The Calendar

This Calendar tool in it’s most basic format consists of three Worksheets My Worksheet, Calendar and Mini

My Worksheet is a worksheet where I want to use the date and do my work

Mini is a Row by Row version of the calendar, it remains hidden at all times but it is busy in the background calculating the dates

Calendar is simply a display of the Mini Data in a convenient 12 Month layout

The Calendar worksheet is where the user can select a Date. If the date is Valid (Yellow), the user selected date is returned to the original worksheet and cell, otherwise the user remains on the Calendar worksheet

The relationship between the Mini and Calendar is all handled by Named Formula which the user doesn’t need to worry about

The VBA

My Worksheet

My Worksheet is a user area where the user is doing his work.

The user can invoke the Calendar Tool in two ways

1. Select any Cell and press the Calendar Button; or
2. Select any Cell and double click it

If the user uses method 1, pressing the calendar Button calls the Show_Calendar subroutine

If the user uses method 2, Double clicking a cell,  the Worksheet_BeforeDoubleClick() event is triggered on the My Worksheet VBA Code Module

The Worksheet_BeforeDoubleClick() event simply calls the Show_Calendar subroutine

Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
  Show_Calendar
End Sub

The Show_Calendar() subroutine in the Calendar_Modules VBA code module subroutine has 2 tasks to perform:

The 2 tasks are to store the location of the cell that the user wants the date in. It is stored in two variables mySht and myRng

These two variables are defined outside the Show_Calendar() subroutine and are declared as Public

This means they are available to all subroutines in the workbook.

Public mySht As String
Public myRng As String

Sub Show_Calendar()

  mysht = ActiveSheet.Name
  myRng = ActiveCell.Address

  Sheets("Calendar").Visible = True
  Sheets("Calendar").Select
End Sub

Calendar

Once on the Calendar two subroutines control the users interaction.

The Worksheet_SelectionChange() and Close_Calendar() subroutines control the users interactions as described below:

The main interaction is controlled by a Worksheet_SelectionChange() event in the calendar Worksheet VBA Code module.

Put simply it monitors when a selection changes and reacts accordingly

If a user selects multiple cells it is ignored

If a user selects a non-Yellow cell it is ignored

If a user selects a Yellow cell the subroutine sets the original users cell to the value of the selected date and formats the cell as appropriate

Private Sub Worksheet_SelectionChange(ByVal Target As Range)

If Target.Cells.Count <> 1 Then Exit Sub

If Target.Interior.Color = 65535 Then 'Set Cell Color requirement here
  Sheets(mysht).Range(myRng) = Target
  With Sheets(mysht).Range(myRng)
    .NumberFormat = "m/d/yyyy" 'Set cells Date format here
    .HorizontalAlignment = xlCenter
    .VerticalAlignment = xlCenter
  End With

  Sheets("Calendar").Visible = False
  Sheets(mysht).Select
End If

End Sub

The Close_Calendar() subroutine is called when the Close Button is selected

It simply hides the Calendar Worksheet and returns the user to the Original worksheet he was working on

Sub Close_Calendar()

  Sheets("Calendar").Visible = False   Sheets(mysht).Select \

End Sub

If you want to enable a user to select any date you can either

1. Set all valid dates to have a color Yellow

2. Remove the date checking section of the code. Comment out the two Lines colored in Red Below:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)

If Target.Cells.Count <> 1 Then Exit Sub

'If Target.Interior.Color = 65535 Then 'Set Cell Color requirement here
  Sheets(mysht).Range(myRng) = Target
  With Sheets(mysht).Range(myRng)
    .NumberFormat = "m/d/yyyy" 'Set cells Date format here
    .HorizontalAlignment = xlCenter
    .VerticalAlignment = xlCenter
  End With

  Sheets("Calendar").Visible = False
  Sheets(mysht).Select
'End If

End Sub

The Final Product

Other Calendar Posts

Chandoo has written a number of posts on calendars, some are shown below:

http://chandoo.org/wp/2013/11/13/pop-up-calendar-excel-vba/

http://chandoo.org/wp/2013/04/09/how-to-create-interactive-calendar-to-highlight-events-appointments-tutorial/

http://chandoo.org/wp/2012/09/12/interactive-pivot-calendar/

http://chandoo.org/wp/tag/printable-calendar/

Conclusion

This workbook has been tested in all versions of PC versions of Excel from 2002 to 2013 and it works a treat.

It is an Excel XLS file and runs in compatibility mode in Excel 2007+

You are free to use and extend it as required.