Added timespan support to export Excel

Export-Excel.ps1

@@ -486,13 +486,19 @@
             #The write-verbose commands have been commented out below - even if verbose is silenced they cause a significiant performance impact and if it's on they will cause a flood of messages.
             Switch ($CellValue) {
                 { $_ -is [DateTime]} {
-                    # Save a date with an international valid format
+                    # Save a date with one of Excel's built in formats format
                     $TargetCell.Value = $_
                     $TargetCell.Style.Numberformat.Format = 'm/d/yy h:mm' # This is not a custom format, but a preset recognized as date and localized.
                     #Write-Verbose  "Cell '$Row`:$ColumnIndex' header '$Name' add value '$_' as date"
                     break
 
                 }
+                { $_ -is [TimeSpan]} {
+                    #Save a timespans with a built in format for elapsed hours, minutes and seconds
+                    $TargetCell.Value = $_
+                    $TargetCell.Style.Numberformat.Format = '[h]:mm:ss'
+                    break
+                } 
                 { $_ -is [System.ValueType]} {
                     # Save numerics, setting format if need be.
                     $TargetCell.Value = $_

README.md

@@ -52,8 +52,9 @@ Install-Module ImportExcel -scope CurrentUser
 Install-Module ImportExcel
 ```
 # New to Aug 14th
-- In Export-Excel improved the catch-all handler for insering values to cope better with nested objects and reduce the number of parse operations 
+- Added support for timespans in Export excel ; set as elapsed hours, mins, secs [h]:mm:sss
-- Added -Calculate switch to Export-Excel and Close-Excel Package; EPPlus needs formulas to OMIT the leading = sign so where formula is set it now strips a leading =  
+- In Export-Excel improved the catch-all handler for insering values to cope better with nested objects (#419) and reduce the number of parse operations 
+- Added -Calculate switch to Export-Excel and Close-Excel Package; EPPlus needs formulas to OMIT the leading = sign so where formula is set it now strips a leading = sign
 - Added -PivotTotals parameter where there was already -NoTotalsInPivot new one allows None, Both, Rows, Columns. (#415)
 - When appending Export-Excel only extended tables and ranges if they were explicitly specified. It now does it automatically. 
 - Compare and Merge worksheet originally had a problem with > 26 columns, I fixed merge turns out I hadn't fixed compare ... I have now 

__tests__/Export-Excel.Tests.ps1

@@ -142,7 +142,7 @@ Describe ExportExcel {
             $ws.cells[1, 1].Value                                       | Should     be  -1
         }
     }
-
+     
     Context "#Examples 3 & 4 # Setting cells for different data types Also added test for URI type" {
 
         if ((Get-Culture).NumberFormat.CurrencySymbol -eq "£") {$OtherCurrencySymbol = "$"}
@@ -177,6 +177,7 @@ Describe ExportExcel {
             Link3            = "xl://internal/sheet1!A1"
             Link4            = "xl://internal/sheet1!C5"
             Process          = (Get-Process -Id $PID) 
+            TimeSpan         = [datetime]::Now.Subtract([datetime]::Today)
         } | Export-Excel  -NoNumberConversion IPAddress, StrLeadZero, StrAltPhone2  -Path $path -Calculate -WarningVariable $warnVar  
         it "Created a new file                                                                     " {
             Test-Path -Path $path -ErrorAction SilentlyContinue         | Should     be $true
@@ -189,7 +190,7 @@ Describe ExportExcel {
         $ws = $Excel.Workbook.Worksheets[1]
         it "Created the worksheet with the expected name, number of rows and number of columns     " {
             $ws.Name                                                    | Should     be "sheet1"
-            $ws.Dimension.Columns                                       | Should     be  25
+            $ws.Dimension.Columns                                       | Should     be  26
             $ws.Dimension.Rows                                          | Should     be  2
         }
         it "Set a date     in Cell A2                                                              " {
@@ -251,8 +252,13 @@ Describe ExportExcel {
         it "Converted a nested object to a string (Y2)                                             " {
              $ws.Cells[2, 25].Value                                     | should     match '^System\.Diagnostics\.Process\s+\(.*\)$'
         }
+        it "Processed a timespan object (Z2)                                                       " {
+             $ws.cells[2, 26].Value.ToOADate()                          | should     beGreaterThan 0
+             $ws.cells[2, 26].Value.ToOADate()                          | should     beLessThan    1
+             $ws.cells[2, 26].Style.Numberformat.Format                 | should     be  '[h]:mm:ss'
+        }
     }
-
+ 
     Context "#               # Setting cells for different data types with -noHeader" {
 
         $path = "$env:TEMP\Test.xlsx"