Basic Powershell script to show appointments from a calendar using the EWS Managed API

One of the more common tasks you might turn to use one of the Exchange API's for is to enumerate appointments in one or more users calendars. This can be useful for a number of reasons and applications and scripts, the EWS Managed API makes getting calendar appointment pretty easy using a script once you understand a few of the fundamentals around how calendar appointment's are stored.

Appointments unlike messages are more complex objects eg where an email would only represent one object in a folder an appointment if its recurring or a recurring exception or a deleted occurrence could represent one more calendar appointments. So its important not just to do a finditems query like you would with Email messages as this will return just the base instances of each appointment object. What you should do when querying for calendar appointments is its important to use a CalendarView, what this means is that when you query for appointments you specify a date range (start and end) for the appointments you what to retrieve and EWS will handle expanding any recurring appointments,deleted occurrences etc and return you what is essentially what you would see in Outlook (which does the same thing). This is a rather simplified explanation if you want to read more check out this sample chapter from Inside Exchange Web Services which is available on MSDN.

So when it comes to putting all this together in Powershell script that will pull all the appointments from a specific calendar we first need to specify the SMTP address of a mailbox you want to access and a Date range you want to check in a few variables

$MailboxName = "gscales@domain.com"
$StartDate = new-object System.DateTime(2009, 08, 01)
$EndDate = new-object System.DateTime(2009, 11, 01)

or maybe you want to look at the appointment for next week

$StartDate = new-object [System.DateTime]::Now
$EndDate = new-object [System.DateTime]::Now.AddDays(7)

Connect to EWS using the currently logged on Credentials the assumes that this account has access to the mailbox is question.

$dllpath = "C:\Program Files\Microsoft\Exchange\Web Services\1.0\Microsoft.Exchange.WebServices.dll"
[void][Reflection.Assembly]::LoadFile($dllpath)
$service = New-Object Microsoft.Exchange.WebServices.Data.ExchangeService([Microsoft.Exchange.WebServices.Data.ExchangeVersion]::Exchange2007_SP1)

$windowsIdentity = [System.Security.Principal.WindowsIdentity]::GetCurrent()
$sidbind = "ldap://<SID/=" + $windowsIdentity.user.Value.ToString() + ">"
$aceuser = [ADSI]$sidbind

$service.AutodiscoverUrl($aceuser.mail.ToString())

Then you need to specify the calendarview object to use

$folderid = new-object Microsoft.Exchange.WebServices.Data.FolderId([Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Calendar,$MailboxName)
$CalendarFolder = [Microsoft.Exchange.WebServices.Data.CalendarFolder]::Bind($service,$folderid)
$cvCalendarview = new-object Microsoft.Exchange.WebServices.Data.CalendarView($StartDate,$EndDate,2000)

and finally query the calendar and return the appointments

$cvCalendarview.PropertySet = new-object Microsoft.Exchange.WebServices.Data.PropertySet([Microsoft.Exchange.WebServices.Data.BasePropertySet]::FirstClassProperties)
$frCalendarResult = $CalendarFolder.FindAppointments($cvCalendarview)
foreach ($apApointment in $frCalendarResult.Items){
$psPropset = new-object Microsoft.Exchange.WebServices.Data.PropertySet([Microsoft.Exchange.WebServices.Data.BasePropertySet]::FirstClassProperties)
$apApointment.load($psPropset)
"Appointment : " + $apApointment.Subject.ToString()
"Start : " + $apApointment.Start.ToString()
"End : " + $apApointment.End.ToString()
"Organizer : " + $apApointment.Organizer.ToString()
"Required Attendees :"
foreach($attendee in $apApointment.RequiredAttendees){
" " + $attendee.Address
}
"Optional Attendees :"
foreach($attendee in $apApointment.OptionalAttendees){
" " + $attendee.Address
}
"Resources :"
foreach($attendee in $apApointment.Resources){
" " + $attendee.Address
}
" "
}

I've put a download of the script here.