Geeking around with PowerShell today trying to add all company holidays to my Outlook calendar. In the script, I’m creating all day appointments and setting the Show As to out of office. Simple enough!

CLOSE Outlook before running the script.

function get-mailfolders {
	$outlookfolders = @()
	$outlook = New-Object -ComObject Outlook.Application
	foreach ($folder in $outlook.Session.Folders){ 

		foreach($mailfolder in $folder.Folders ) {
			$olkf = New-Object PSObject -Property @{
				Path = $($mailfolder.FullFolderPath)
				EntryID = $($mailfolder.EntryID)
				StoreID = $($mailfolder.StoreID)
			} 

			$outlookfolders += $olkf
		}
	}
	$outlookfolders
}

$outlook = new-object -com Outlook.Application
$folder = get-mailfolders | where {$_.Path -like "*calendar*" -and $_.Path -and $_.Path -like "*$mailbox*"}
$calendar = $outlook.Session.GetFolderFromID($folder.EntryID, $folder.StoreID) 

$holidays = @{"01/01/2017"="New Year’s Day"; "01/16/2017"="Martin Luther King Day"; "02/02/2017"="Presidents Day"; "05/29/2017"="Memorial Day"; `
	"07/04/2017"="Independence Day"; "11/4/2017"="Labor Day"; "11/23/2017"="Thanksgiving Break"; "11/24/2017"="Thanksgiving Break"; "12/25/2017"="Christmas Day"}

foreach($holiday in $holidays.GetEnumerator() | Sort Key)
{
	[string]$hName = $holiday.Value
	$hDate = Get-Date $holiday.Key

	$appt = $calendar.Items.Add(1)
	$appt.Start = $holiday.key.ToString()
	$appt.AllDayEvent = $true
	$appt.Subject = $hName
	$appt.Body = $hName

	<#
	Show As / Status
	0 = Free
	1 = Tentative
	2 = Busy
	3 = Out of Office
	#>
	$appt.BusyStatus = 3

	$appt.Save()
}

You might see this error if you haven’t CLOSED Outlook:
new-object : Retrieving the COM class factory for component with CLSID {0006F03A-0000-0000-C000-000000000046} failed due to

the following error: 80080005 Server execution failed (Exception from HRESULT: 0x80080005 (CO_E_SERVER_EXEC_FAILURE)).

At C:\Code\PS\SPO_BHP\Set_Holidays.ps1:19 char:12

+ $outlook = new-object -com Outlook.Application

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

+ CategoryInfo : ResourceUnavailable: (:) [New-Object], COMException

+ FullyQualifiedErrorId : NoCOMClassIdentified,Microsoft.PowerShell.Commands.NewObjectCommand
This post helped guide me in the right direction:

Create a calendar item