./jobs|orders/set_run_time web service raises an error if a requested run_time has attributes but no child elements

Current Situation

The web services ./orders/set_run_time and ./jobs/set_run_time validate the requested run_time.
The validation raises an error if the run_time doesn't have child elements but attributes.

Desired Behavior

A run_time can have attributes and no child elements. The run_time validation should consider it.