Is there a way to test SharePoint Online retention policies without waiting a day? Tried to change the policy from Created to Date and Time + 1 day and even when I changed the calendar to a day before the workflow won't start. Any help will be greatly appreciated.
No there isn't. There are 2 timer jobs that run that we do not have control of.
The first timer job will identify things that have met their retention date and flag them as needing action. The next timer job runs through and handles the flagged items and does the required action (deleting the item, moving it, executing a workflow, etc).
Last I knew, and based on our testing, these were weekly timer jobs. On-prem, we had the ability to make them daily, but we do not have that luxury in SharePoint Online.