I was also looking for this information, i am building a workflow that i want to then re-use for customers and ofc as a marketing and value preposition, display the saved time.
a very simple but yet working solution to meet all requirements would be to add the “time_saved” value as a settings field in every node.
if you fill a value at the end of the workflow element and the final node runs, the time_saved value gets added to the main workflow statistic.
so if my workflow e.g. just looks up a caller ID in CRM and plays it back to my voice agent, this might save me 15 - 30 seconds, while booking an appointment might be another 30 but a full AI based summary of the call in addition to the “call_duration” value transferred via postcall webhook to n8n is a whole other story.
So i wish the time saved to be open for JSON values as well
options like i described would at least solve my problem instantly.