Use of UTC date range
If the value in the request body were true, then the Zenput server would consider the GMT (Greenwich Mean Time) of form submissions' dates to determine whether or not to include those form submissions in its selection, and hence, to also determine whether or not to include the corresponding objects in the form_submissions array in the response payload.
Otherwise, if the value in the request body were false, then the Zenput server would consider the local time of form submissions' dates for the same purpose.
Important: The time frame that is delimited by the dates specified in date_start and date_end would alter the Zenput server's selection. The time frame could narrow that selection.
Note: The default value of use_utc_date_range is true.