How to specify deferred deletion on a table with a number of hours instead of a number of days ?

As specified in the documentation, the delete delay is defined in days and is of type Integer. https://docs.oneidentity.com/bundle/one-identity-manager_configuration_9.3/page/sources/config/schema/dbmdialogtabledeletedelay.htm 

To use fractions of a day, you can configure a schedule that runs hourly (or more often, but that depends on your exact requirements), and triggers the event EXECUTE for the items in DialogDeferredOperations you want to delete. In your case, these are the ones that reached the 1 hour based on the property XDateInserted of these items in DialogDeferredOperations.

Perfect, this is a flexible approach that meets my needs. Thank you very much, Markus. Your brief explanation would be worth adding to the documentation.