Call for ArcGIS Enterprise experts! This is a queston about UTC and local time handling when publishing registered dynamic query layers to Enterprise.
Use case:
Publish a map image service that contains XY event layer that is based on a referenced SQL query table. The SQL query table is a simple SELECT query with a field of datetime data type. The datetime value is stored as a plain local time value without timezone and daylight saving information.
When pulishing to ArcGIS Enterprise via ArcGIS Pro Share as Web Layer, the local time zone and daylight saving option are configured in the sharing wizard.
The issue:
ArcGIS Enterprise doesn't respect the time zone and daylight saving configuration for such dynamic layers. Instead, it treats the value as UTC and convert it to local e.g. adding 13hours for NZ daylight saving time.
However, there is no issue if published from a static feature class from a file gdb. Extactly same data and same publish process.
Software:
Client - ArcGIS Pro 2.8
Server - ArcGIS Enterprise 10.9
Test: Publish a map with two layers of exactly same data, one from registered feature class and one based on a SQL query table.
1. Prepare workspace as below. Both layers are registered on the target ArcGIS Server.

2. Check value from local ArcGIS Pro using identify and popup. Same value 13/10/2021, 12:33pm for both layers.

3. Publish as map image layer.

configure timezone and daylight saving

4. Publish to Enterprise is successful. Check on map viewer from Portal.

Question:
With timezone and daylight saving configured during publish process, why Enterprise treats feature class layer correctly but not Event layer based on SQL query table?
For the query table and XY event layer, no matter what timezone you choose during the publish stage, NZ+12:00 or UTC or <None> or any other, Enterprise always treats it as UTC and converts it to local time, in my case, +1300.
Any ideas and insights would be much appreciated!
Thanks,
Hua