Is target.sent.end.time populated when there is no response from the target(backend)

[#1]

I am using target.sent.end.time variable to capture the time the request was sent out in my logs. There are some gateway timeouts that being experienced and noticed that the variable is not getting populated. Does the target.sent.end.time get populated if the request is sent out to the backend and apigee times out while waiting for the response?