Why and when is "CompletedTime" null?

[VictorioBerra]

I noticed that if a step fails, a workflow will not have a completed time, and be in a runnable state.

However, if you set the DefaultErrorBehavior to something like Terminated, you get a completed time.

Wouldn't one consider a workflow ending for any reason being "complete"?

[VictorioBerra]

I think to answer this, a workflow gets a completed time when it will be in a state that does not allow for a retry.