Date only and time only fields are captured in the local device time. As such, they're always displayed as the raw, local time values, without any time zone adjustment.
Time-zone's can be changed through the web platform to be adjusted according to the logged in user, or organization set timezone.
Our API mirrors the above. Date only and time only fields display in raw format, e.g DD-MM-YYYY or HH:MI:SS values. Date/time fields display as ISO 8601 format (e.g. time zone inclusive).
All other date/time values found on our API accept and return ISO 8601 format.