The response to the requests uses the Roundtrip format: 2008-04-10T06:30:00.0000000-07:00
where -07:00 is UTC offset which is set on the portal.
In case the portal uses UTC time without any offset, the date/time format in the response will be the following: 2008-04-10T06:30:00.0000000Z.
As for the request, only date can be send in it: 2008-04-10.
If you use the date/time in URL request, colons must be avoided and replaced by hyphens: 2008-04-10T06-30-00.000Z.
Please note that the UTC date and time without the offset are used in this case.
Yes. More information you can find in the Request filtering section.