In order to enable temporal subtraction you must set the supports_temporal_subtraction database feature flag to True and implement the DatabaseOperations.subtract_temporals() method. This method should return the SQL and parameters required to compute the difference in microseconds between the lhs and rhs arguments in the datatype used to store DurationField.
In order to enable temporal subtraction you must set the supports_temporal_subtraction database feature flag to True and implement the DatabaseOperations.subtract_temporals() method. This method should return the SQL and parameters required to compute the difference in microseconds between the lhs and rhs arguments in the datatype used to store DurationField.