Using the PSAtera module to automatically switch tickets from Pending to Open when the "Scheduled For" field is today.

Set-ScheduledTickets.ps1

Import-Module PSAtera -MinimumVersion 1.4.0
$Tickets = Get-AteraTicketsFiltered -Pending

foreach($Ticket in $Tickets) {
  $ScheduledDate = Get-AteraCustomValue -ObjectType Ticket -ObjectID $Ticket.TicketID -FieldName "Scheduled For"
  if ($null -eq $ScheduledDate.ValueAsDateTime) { return }
  if ((Get-Date -Date $ScheduledDate.ValueAsDateTime) -le (Get-Date)) {
    Set-AteraTicket -TicketID $Ticket.TicketID -TicketStatus "Open"
  }
}