Nevermind. I was thinking about this for some time and got totaly stuck and blind for the obvious.

The code below requires the WeekNumber() and DateCalc() UDFs.

 Code:
Break on

$day1 = udfDatePicker()

;$day1 = "2014/07/28"
$day2 = DateCalc($day1, 1)
$day3 = DateCalc($day2, 1)
$day4 = DateCalc($day3, 1)
$day5 = DateCalc($day4, 1)

$week = WeekNumber(Join(Split($day1, "/"), "-"))
? "Week: " + $week
? "Day1: " + $day1
? "Day2: " + $day2
? "Day3: " + $day3
? "Day4: " + $day4
? "Day5: " + $day5

Sleep 5

; Function udfDatePicker()
; 
; Inspired by Bruno's post here: http://www.kixforms.org/forum/viewtopic.php?t=672 
; 
; udfDatePicker() - Allow user to select a date from a calendar. 
; 
; Parameters:   All parameters are optional. 
;            sTitle   - Tool window title 
;            sStartday      - The day that first appears in the tool 
;            iTodayButton   - Does the "Today" button appear on the tool (true / false) 
;                          Default is false 
;            $asSpecialDays   - Array or space delimited list of special days which are 
;                          highlighted in an alternate colour.  Default is today. 
;            $sButtonStyle   - How the individual dat buttons appear.  Default is flat "popup" 
;                          style, use "2" for a raised button effect. 
;            $sLowDay      - The earliest day that can be selected. 
;            $sHighDay      - The latest day that can be selected. 
; 
; Examples 
; -------- 
; Display this month, highlight today 
;   $v=udfDatePicker() 
; 
; Only allow user to select my birthday :) 
;    $v=udfDatePicker("Special day","1966/12/21",,"1966/12/21",2,"1966/12/21","1966/12/21") 
; 
; Highlight the 10th and 20th this month, don't allow user to select days after today 
;   $v=udfDatePicker("","",1,""+@YEAR+"/"+@MONTHNO+"/10 "+@YEAR+"/"+@MONTHNO+"/20",,"",@DATE) 
; 
; 
; 
;   $sMyBirthday= 
; Amendement History 
; ------------------ 
;   20091127 14:30   Richard Howarth <rhowarth@harsco.com> 
;               Function initially created. 
;
Function udfDatePicker( 
	Optional $sTitle, 
	Optional $sStartDay, 
	Optional $iTodayButton, 
	Optional $asSpecialDays, 
	Optional $sButtonStyle, 
	Optional $sLowDay, 
	Optional $sHighDay 
	) 
	Dim $frm, $lblMonth, $btnPrev, $btnPrevYr, $btnNext, $btnNextYr, $btnToday 
	Dim $sDayHeader 
	Dim $s, $i 
	Dim $btnList[37] 
	Dim $iDaynoX, $iDaynoHeight, $iDaynoWidth 
	Dim $sAction 
	Dim $sToolColour, $sEvenDayColour, $sOddDayColour, $sTodayColour 
	Dim $iUpdate 
	Dim $iMonth, $iYear 
	Dim $iLastDay, $iFirstDay 
	Dim $aiDaysInMonth, $asMonthName 
	Dim $sThisDay 
	$sToolColour = LightGray 
	$sEvenDayColour = $sToolColour 
	$sOddDayColour = Silver 
	$sTodayColour = PaleGoldenrod 
	$aiDaysInMonth = x, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 
	$sDayHeader = "10:Mo 37:Tu 64:We 91:Th 118:Fr 140:Sa 166:Su" 
	$asMonthName = "January", "February", "March", "April", 
	"May", "June", "July", "August", 
	"September", "October", "November", "December" 
	$iDaynoX = 50   ; Offset for day 
	$iDaynoHeight = 20 ; Height of day button 
	$iDaynoWidth = 25 ; Width of day button 
	If $sLowDay = "" $sLowDay = "0000/00/00" EndIf 
	If $sHighDay = "" $sHighDay = "9999/99/99" EndIf 
	If VarType($asSpecialDays) & 8192 $asSpecialDays = Join($asSpecialDays) EndIf 
	If $asSpecialDays = "" $asSpecialDays = @DATE EndIf 
	$asSpecialDays = Split($asSpecialDays) 
	If $sStartDay = "" 
		$iMonth = CInt(@MONTHNO) 
		$iYear = CInt(@YEAR) 
	Else 
		$iMonth = CInt(Split($sStartDay, "/")[1]) 
		$iYear = CInt(Split($sStartDay, "/")[0]) 
	EndIf 
	$iUpdate = 1 
	If Not IsDeclared($_funDatePicker_KiXform) 
		Global $_funDatePicker_KiXform 
	EndIf 
	If VarType($_funDatePicker_KiXform) <> 9 
		$_funDatePicker_KiXform = CreateObject("KiXtart.System") 
		If @ERROR Exit @ERROR EndIf 
	EndIf 
	$frm = $_funDatePicker_KiXform.Form() 
	If @ERROR Exit @ERROR EndIf 
	;$frm.icon = $_funDatePicker_KiXform.BuiltinIcons(101)
	$frm.formborderstyle = 1
	$frm.maximizebox = 0
	$frm.minimizebox = 0
	$frm.width = 210 
	$frm.height = 215
	$frm.text = "Select a date"
	$lblMonth = $frm.Controls.Label() 
	$lblMonth.Bounds = 30, 10, $frm.width - 70, 18 
	$lblMonth.textalign = 32 
	$lblMonth.BackColor = $sToolColour 
	$lblMonth.BorderStyle = FixedSingle 
	$btnPrevYr = $frm.Controls.ToolButton() 
	$btnPrevYr.Icon = 27 
	$btnPrevYr.Left = 0 
	$btnPrevYr.height = 15 
	$btnPrevYr.width = 15 
	$btnPrevYr.top = 10 
	$btnPrevYr.flatstyle = 1 
	$btnPrevYr.onclick = "PreviousYr" 
	$btnPrev = $frm.Controls.ToolButton() 
	$btnPrev.Icon = 27
	$btnPrev.Left = 15 
	$btnPrev.height = 15 
	$btnPrev.width = 15 
	$btnPrev.top = 10 
	$btnPrev.flatstyle = 1 
	$btnPrev.onclick = "Previous" 
	If $iTodayButton 
		$frm.height = 230 
		$btnToday = $frm.Controls.ToolButton() 
		$btnToday.text = "Today" 
		$btnToday.Left = ($frm.width /2) - 25 
		$btnToday.height = 20 
		$btnToday.width = 40 
		$btnToday.top = $frm.Height - 55 
		$btnToday.onclick = "Today" 
		$btnToday.BackColor = $sToolColour 
		$btnToday.FlatStyle = 1 
	EndIf 
	$btnNext = $frm.Controls.ToolButton() 
	$btnNext.Icon = 28 
	$btnNext.Left = $frm.width - 40 
	$btnNext.height = 15 
	$btnNext.width = 15 
	$btnNext.top = 10 
	$btnNext.onclick = "Next" 
	$btnNext.FlatStyle = 1 
	$btnNextYr = $frm.Controls.ToolButton() 
	$btnNextYr.Icon = 28 
	$btnNextYr.Left = $frm.width - 25 
	$btnNextYr.height = 15 
	$btnNextYr.width = 15 
	$btnNextYr.top = 10 
	$btnNextYr.flatstyle = 1 
	$btnNextYr.onclick = "NextYr" 
	; Create day header labels 
	For Each $s in Split($sDayHeader) $frm.PrintXY(Split($s, ":")[0], 30, Split($s, ":")[1]) Next 
		For $i = 0 to 36 
			$btnList[$i] = $frm.ToolButton() 
			$btnList[$i] .Location = 10 + $iDaynoWidth * ($i mod 7), $iDaynoX + $iDaynoHeight * ($i /7) 
			$btnList[$i] .width = $iDaynowidth 
			$btnList[$i] .height = $iDaynoHeight 
			$btnList[$i] .BorderStyle = 1 
			$btnList[$i] .FlatStyle = $sButtonStyle 
		Next 
		$labFrame = $frm.Controls.Label() 
		$labFrame.BorderStyle = 1 
		$labFrame.Text = "" 
		$labFrame.Width = 181 
		$labFrame.Height = 106 
		$labFrame.Top = 47 
		$labFrame.Left = 7 
		$frm.Show 
		While $frm.Visible 
			If $iUpdate 
				$lblMonth.Text = $asMonthName[$iMonth - 1] + " " + $iYear 
				; Fix leap day for this year 
				$aiDaysInMonth[2] = 28 + ((($iYear mod 4 = 0) And ( $iYear mod 100 > 0 )) Or ( $iYear mod 400 = 0 )) 
				; Calculate the offset for the first day of the month, algorithm taken from: 
				;   http://www.faqs.org/faqs/calendars/faq/part1/index.html#ixzz0Y3svssjS 
				Dim $a, $y, $m 
				$a = (14 - $iMonth) /12 
				$y = $iYear - $a 
				$m = $iMonth + 12 * $a - 2 
				; The "1" here is hardcoded for the first day of the month 
				$iFirstDay = (1 + $y + $y /4 - $y /100 + $y /400 + (31 * $m) /12) mod 7 
				; Algorithm gives Sunday=0, fix date  to ease calculation (Sunday=7) 
				$iFirstDay = $iFirstDay + 7 * ($iFirstDay = 0) 
				If $iFirstDay > 5 
					$labFrame.Height = 126 
				Else 
					$labFrame.Height = 106 
				EndIf 
				$btnPrev.enabled = TRUE 
				$btnPrevYr.enabled = TRUE 
				$btnNext.enabled = TRUE 
				$btnNextYr.enabled = TRUE 
				For $i = 0 to 36 
					If ($i + 1) >= $iFirstDay And ( $i - $iFirstDay + 1 ) < $aiDaysInMonth[$iMonth] 
						$btnList[$i] .Text = ($i + 2 - $iFirstDay) 
						$sThisDay = CStr($iYear) + "/" + Right("0" + $iMonth, 2) + "/" + Right("0" + $btnList[$i] .Text, 2) 
						$btnList[$i] .OnClick = 'btnDayNo ' + $sThisDay 
						$btnList[$i] .visible = TRUE 
						$btnList[$i] .Backcolor = IIf(($i mod 7) mod 2, $sOddDayColour, $sEvenDayColour) 
						If 1 + AScan($asSpecialDays, $sThisDay) And $sTodayColour $btnList[$i] .Backcolor = $sTodayColour EndIf 
						If $sThisDay < $sLowDay 
							$btnList[$i] .enabled = FALSE 
							$btnPrev.enabled = FALSE 
							$btnPrevYr.enabled = FALSE 
						Else 
							$btnList[$i] .enabled = TRUE 
							$btnPrev.enabled = TRUE 
							$btnPrevYr.enabled = TRUE 
						EndIf 
						If $sThisDay > $sHighDay 
							$btnList[$i] .enabled = FALSE 
							$btnNext.enabled = FALSE 
							$btnNextYr.enabled = FALSE 
						Else 
							$btnList[$i] .enabled = TRUE 
							$btnNext.enabled = TRUE 
							$btnNextYr.enabled = TRUE 
						EndIf 
					Else 
						$btnList[$i] .visible = FALSE 
					EndIf 
				Next 
				$iUpdate = 0 
			EndIf 
			$sAction = $frm.DoEvents 
			Select 
				Case $sAction = "" 
					; No action 
				Case $sAction = "Previous" 
					$iMonth = $iMonth - 1 
					If $iMonth < 1 $iMonth = 12 $iYear = $iYear - 1 EndIf 
					$iUpdate = 1 
				Case $sAction = "Next" 
					$iMonth = $iMonth + 1 
					If $iMonth > 12 $iMonth = 1 $iYear = $iYear + 1 EndIf 
					$iUpdate = 1 
				Case $sAction = "PreviousYr" 
					$iMonth = $iMonth - 12 
					If $iMonth < 1 $iMonth = 12 - Abs($iMonth) $iYear = $iYear - 1 EndIf 
					$iUpdate = 1 
				Case $sAction = "NextYr" 
					$iMonth = $iMonth + 12 
					If $iMonth > 12 $iMonth = Abs($iMonth) - 12 $iYear = $iYear + 1 EndIf 
					$iUpdate = 1 
				Case $sAction = "Today" 
					$iMonth = @MONTHNO 
					$iYear = @YEAR 
					$iUpdate = 1 
				Case Split($sAction)[0] = "btnDayNo" 
					$udfDatePicker = Split($sAction)[1] 
					$frm.hide 
				Case Default 
					"Unexpected event: " + $sAction + @CRLF 
			EndSelect 
		Loop 
		$frm = 0 
		Exit 0 
	EndFunction
_________________________
Mart

- Chuck Norris once sold ebay to ebay on ebay.