Different timezones don't work using C#

[kiragengis]

Describe the bug
When I use a Time zone different than the "Eastern Standard Time" I receive the error:
ServiceException: Code: BadRequest
Message: Invalid filter clause: The DateTimeOffset text '2023-09-28T21:14:43.4437014' should be in format 'yyyy-mm-ddThh:mm:ss('.'s+)?(zzzzzz)?' and each field value is within valid range.
Inner error:
AdditionalData:
date: 2023-09-29T15:45:02
request-id: ***
client-request-id: ***
ClientRequestId: ***

To Reproduce
Steps to reproduce the behavior:
This is how I create an instance of MicrosoftEmailHelper:

MicrosoftEmailHelper emailHelper = new MicrosoftEmailHelper();
TimeZoneInfo indiaTimeZone = TimeZoneInfo.FindSystemTimeZoneById("India Standard Time");
DateTimeOffset indiaTime = TimeZoneInfo.ConvertTime(DateTimeOffset.UtcNow, indiaTimeZone );

This is my request:

return client.Me.MailFolders.Inbox.Messages.Request()
                                  .Filter(filter) //can't use order by when use filters
                                  .Select(m => new { m.Subject, m.ReceivedDateTime, m.From, m.Body })
                                  .GetAsync().Result;

I create the date this way:
string filter = $"startswith(subject, '{subject}') and ReceivedDateTime ge {received_from.ToString("o")}";

As a result string within filter will be: startswith(subject, 'SUBJECT OF MY EMAIL') and ReceivedDateTime ge 2023-09-28T21:10:36.2266736+05:30

Expected behavior
I should be able to obtain the list of emails

Current results
Error:
ServiceException: Code: BadRequest
Message: Invalid filter clause: The DateTimeOffset text '2023-09-28T21:14:43.4437014' should be in format 'yyyy-mm-ddThh:mm:ss('.'s+)?(zzzzzz)?' and each field value is within valid range.
Inner error:
AdditionalData:
date: 2023-09-29T15:45:02
request-id: ***
client-request-id: ***
ClientRequestId: ***

[MartinM85]

I think you need to encode + as %2B.

startswith(subject, 'SUBJECT OF MY EMAIL') and ReceivedDateTime ge 2023-09-28T21:10:36.2266736%2B05:30

You mentioned that you can't use orderby. I would recommend to follow the guideline in the documentation.

Using filter and orderby in the same query

---

When using $filter and $orderby in the same query to get messages, make sure to specify properties in the following ways:

• Properties that appear in $orderby must also appear in $filter.
• Properties that appear in $orderby are in the same order as in $filter.
• Properties that are present in $orderby appear in $filter before any properties that aren't.

Failing to do this results in the following error:

• Error code: InefficientFilter
• Error message: The restriction or sort order is too complex for this operation.

---

[kiragengis]

Thank you for your answer @MartinM85. You were totally right. That solved my problem. I will read the guideline in the documentation about orderby. This is a code I inherited :(