I have created QueryTable from MainTable showing data sorted by StartDateTime. Is there a formula or way of updating the added column QueryTable.PreviousEndDateTime with the value of QueryTable.EndDateTime from the previous row in the query for each record in the query?

The end result is to show the MainTable data in a form by start date/time order whilst alerting that the previous records end date/time field is different to the current records start date/time field. Records in MainTable may be in any order as it stores times on each job for different people.