Skip to main content

Understanding the TimeZone setting with the GetUserAvailability Operation in Exchange Web Services in Exchange 2007

Updated 12/7/2007 with the proper method of using the registry thanks to Benjamin Spain from MSFT for pointing this out

Using TimeZones is very different in EWS then it is in other Exchange API’s like CDOEX where the time zone configuration itself is stored in the DLL (hence causing the need to patch the dll every time the government decides to change the date for Daylight savings). I’ve been working on some GetUserAvailibility code and it’s been a bit of a struggle to get my head around the new format and how to make this flexible (eg no hard coding Bias values or Daylight Saving settings) in the code I’m using so I thought I’d put together a post to share what I’ve learned.

To populate the TimeZone information in a GetUserAvailability Operation you need to set the properties in a GetUserAvailabilityRequestType object so the following nodes will be populated in the SOAP request.

<TimeZone>
<Bias>...</Bias>
<StandardTime>...</StandardTime>
<DaylightTime>...</DaylightTime>
</TimeZone>


Theses nodes should reflect the setting from the registry timezone keys under SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\ for whatever timezone you want to make the request from. Not all timezones use DST but you still have to fill out both standardTime and daylightTime nodes in the case where you have no Daylight setting.

To read the timezone setting from the registry you need to deal with two different data structures which are documented on MSDN the first is the

TIME_ZONE_INFORMATION http://msdn2.microsoft.com/en-us/library/ms725481.aspx

Make sure you read the StandardDate section of this doco this is very important in relation to the rest of the code.

and

SYSTIME http://msdn2.microsoft.com/en-us/library/ms724950.aspx

To find the correct node in the registry the method that I've used was to get the StandardName from TimeZone.CurrentTimeZone.StandardName which i found usually corresponds to the Key name under SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\. Under that Key you need to get the TZI value which is a binary registry key which stores information in the TIME_ZONE_INFORMATION structure.

To help parse this information i used a few structs as the format defines the first 4 bytes relate to the default Bias the next 4 bytes are the standardTime Bias (usually always 0) and the next four bytes are the daylightTime Bias. The remaining bytes are comprised of 16bit words that define 2 SYSTIME structures one for standard time and one for daylight time. These structures basically tell you when DST and StandardTime starts and Ends. To use these in a GetUserAvailibility operation you need to translate them into a SerializableTimeZoneTime object.

So to put this together is some code it would look like the following there a downloadable version here

class Program
{
private struct SYSTEMTIME
{
public Int16 wYear;
public Int16 wMonth;
public Int16 wDayOfWeek;
public Int16 wDay;
public Int16 wHour;
public Int16 wMinute;
public Int16 wSecond;
public Int16 wMilliseconds;
public void getSysTime(byte[] Tzival,int offset) {
wYear = BitConverter.ToInt16(Tzival, offset);
wMonth = BitConverter.ToInt16(Tzival, offset + 2);
wDayOfWeek = BitConverter.ToInt16(Tzival, offset + 4);
wDay = BitConverter.ToInt16(Tzival, offset + 6);
wHour = BitConverter.ToInt16(Tzival, offset + 8);
wMinute = BitConverter.ToInt16(Tzival, offset + 10);
wSecond = BitConverter.ToInt16(Tzival, offset + 12);
wMilliseconds = BitConverter.ToInt16(Tzival, offset + 14);
}
}
private struct REG_TZI_FORMAT
{
public Int32 Bias;
public Int32 StandardBias;
public Int32 DaylightBias;
public SYSTEMTIME StandardDate;
public SYSTEMTIME DaylightDate;
public void regget(byte[] Tzival) {
Bias = BitConverter.ToInt32(Tzival, 0);
StandardBias = BitConverter.ToInt32(Tzival, 4);
DaylightBias = BitConverter.ToInt32(Tzival, 8);
StandardDate = new SYSTEMTIME();
StandardDate.getSysTime(Tzival, 12);
DaylightDate = new SYSTEMTIME();
DaylightDate.getSysTime(Tzival, 28);
}

}

static void Main(string[] args)
{
String tzString = @"SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\" + TimeZone.CurrentTimeZone.StandardName;
RegistryKey TziRegKey = Registry.LocalMachine;
TziRegKey = TziRegKey.OpenSubKey(tzString);
byte[] Tzival = (byte[])TziRegKey.GetValue("TZI");
REG_TZI_FORMAT rtRegTimeZone = new REG_TZI_FORMAT();
rtRegTimeZone.regget(Tzival);
GetUserAvailabilityRequestType fbRequest = new GetUserAvailabilityRequestType();
fbRequest.TimeZone = new SerializableTimeZone();
fbRequest.TimeZone.DaylightTime = new SerializableTimeZoneTime();
fbRequest.TimeZone.StandardTime = new SerializableTimeZoneTime();
fbRequest.TimeZone.Bias = rtRegTimeZone.Bias;
fbRequest.TimeZone.StandardTime.Bias = rtRegTimeZone.StandardBias;
fbRequest.TimeZone.DaylightTime.Bias = rtRegTimeZone.DaylightBias;
if (rtRegTimeZone.StandardDate.wMonth != 0)
{
fbRequest.TimeZone.StandardTime.DayOfWeek = ((DayOfWeek)rtRegTimeZone.StandardDate.wDayOfWeek).ToString();
fbRequest.TimeZone.StandardTime.DayOrder = (short)rtRegTimeZone.StandardDate.wDay;
fbRequest.TimeZone.StandardTime.Month = rtRegTimeZone.StandardDate.wMonth;
fbRequest.TimeZone.StandardTime.Time = String.Format("{0:0#}:{1:0#}:{2:0#}", rtRegTimeZone.StandardDate.wHour, rtRegTimeZone.StandardDate.wMinute, rtRegTimeZone.StandardDate.wSecond);
}
else {
fbRequest.TimeZone.StandardTime.DayOfWeek = "Sunday";
fbRequest.TimeZone.StandardTime.DayOrder = 1;
fbRequest.TimeZone.StandardTime.Month = 1;
fbRequest.TimeZone.StandardTime.Time = "00:00:00";

}
if (rtRegTimeZone.DaylightDate.wMonth != 0)
{
fbRequest.TimeZone.DaylightTime.DayOfWeek = ((DayOfWeek)rtRegTimeZone.DaylightDate.wDayOfWeek).ToString();
fbRequest.TimeZone.DaylightTime.DayOrder = (short)rtRegTimeZone.DaylightDate.wDay;
fbRequest.TimeZone.DaylightTime.Month = rtRegTimeZone.DaylightDate.wMonth;
fbRequest.TimeZone.DaylightTime.Time = "00:00:00";
}
else {
fbRequest.TimeZone.DaylightTime.DayOfWeek = "Sunday";
fbRequest.TimeZone.DaylightTime.DayOrder = 5;
fbRequest.TimeZone.DaylightTime.Month = 12;
fbRequest.TimeZone.DaylightTime.Time = "23:59:59";

}
Console.WriteLine("end");

}

}





Popular posts from this blog

The MailboxConcurrency limit and using Batching in the Microsoft Graph API

If your getting an error such as Application is over its MailboxConcurrency limit while using the Microsoft Graph API this post may help you understand why. Background   The Mailbox  concurrency limit when your using the Graph API is 4 as per https://docs.microsoft.com/en-us/graph/throttling#outlook-service-limits . This is evaluated for each app ID and mailbox combination so this means you can have different apps running under the same credentials and the poor behavior of one won't cause the other to be throttled. If you compared that to EWS you could have up to 27 concurrent connections but they are shared across all apps on a first come first served basis. Batching Batching in the Graph API is a way of combining multiple requests into a single HTTP request. Batching in the Exchange Mail API's EWS and MAPI has been around for a long time and its common, for email Apps to process large numbers of smaller items for a variety of reasons.  Batching in the Gr...

Exporting and Uploading Mailbox Items using Exchange Web Services using the new ExportItems and UploadItems operations in Exchange 2010 SP1

Two new EWS Operations ExportItems and UploadItems where introduced in Exchange 2010 SP1 that allowed you to do a number of useful things that where previously not possible using Exchange Web Services. Any object that Exchange stores is basically a collection of properties for example a message object is a collection of Message properties, Recipient properties and Attachment properties with a few meta properties that describe the underlying storage thrown in. Normally when using EWS you can access these properties in a number of a ways eg one example is using the strongly type objects such as emailmessage that presents the underlying properties in an intuitive way that's easy to use. Another way is using Extended Properties to access the underlying properties directly. However previously in EWS there was no method to access every property of a message hence there is no way to export or import an item and maintain full fidelity of every property on that item (you could export the...

EWS Create Mailbox folder Powershell module for Exchange and Office365 Mailboxes

This is a rollup post for a couple of scripts I've posted in the past for creating folders using EWS in an Exchange OnPremise or Exchange online Cloud mailbox. It can do the following Create a Folder in the Root of the Mailbox Create-Folder -Mailboxname mailbox@domain.com -NewFolderName test Create a Folder as a SubFolder of the Inbox Create-Folder -Mailboxname mailbox@domain.com -NewFolderName test -ParentFolder '\Inbox' Create a Folder as a SubFolder of the Inbox using EWS Impersonation Create-Folder -Mailboxname mailbox@domain.com -NewFolderName test -ParentFolder '\Inbox' -useImpersonation Create a new Contacts Folder as a SubFolder of the Mailboxes Contacts Folder Create-Folder -Mailboxname mailbox@domain.com -NewFolderName test -ParentFolder '\Contacts' -FolderClass IPF.Contact Create a new Calendar Folder as a SubFolder of the Mailboxes Calendar Folder Create-Folder -Mailboxname mailbox@domain.com -NewFolderName test -Parent...
All sample scripts and source code is provided by for illustrative purposes only. All examples are untested in different environments and therefore, I cannot guarantee or imply reliability, serviceability, or function of these programs.

All code contained herein is provided to you "AS IS" without any warranties of any kind. The implied warranties of non-infringement, merchantability and fitness for a particular purpose are expressly disclaimed.