If you would have get the above error in orchestrator, pls follow below steps.
Please navigate to the settings option from right-side of Orchestrator screen, as below.
select the Time-zone from where you are and click on save button.
Then go-back to trigger option and type in the time zone (whatever time zone you have selected in settings only that time zone will accepts, other Time-zones will show error)
Thanks,
Mahammad Gouse