OnTime API: Date Format and Time Zone

Date and time values are formatted using the ISO 8601 format and should be expressed as Coordinated Universal Time (UTC).
This may require that the value is formatted and converted to and from local time settings. Submitting date/time values using other formats or time zones may lead to inconsistent results or errors.
For example, 10:20 AM on April 12, 2021, Pacific Daylight Time (-7:00) would be submitted as:
2021-04-12T17:20Z