REST GET and (localized) datetime attributes

scenario

my mendix application publishes a REST GET api with a datetime attribute in the request
In the response i return database records with datetime attribute >= requested datetime attribute
Both the request and response datetime attribute are defined in nonpersistent domain attributes with property Localize set to Yes.

example

1. My request in SoapUI contains "2017-05-12 14:20:50.000"
   NB: the time is specified as a localized time
2. in the debugger i see:  UTC time: 2017-05-12 12:20:50.000 Session time: 2017-05-12 14:20:50.000 +0200
   NB: the time is interpreted by Mendix as a localized time. Adding a 'Z' in the timestring at 1. does not make a difference. Mendix keeps seeing it as localized 
3. My response in the debugger contains: UTC time: 2017-05-12 13:51:54.866 Session time: 2017-05-12 15:51:54.866 +0200
   NB: this is a correct selection, as the response time >= request time
4. My response in SoapUI "2017-05-12T13:51:54.866Z"
   NB: this is a correct result, however presented in UTC or Zulu time.

problem

To a user this is confusing:

• i cannot manipulate the fact Mendix interprets request as localized
• i cannot manipulate the fact Mendix responds with a UTC time
• for the user it is importent that both request and response time are the same type: either both UTC or both localized

Any ideas?