Message ID for given event time

[Brian Candler]

When using the "reader" API, is there a way to get the message ID 
closest to a given event time?

That is, like "reset-cursor" on subscriptions, but for the reader API.  
At the moment I can only see how to start from the very beginning or the 
very end of a topic.

I couldn't find an existing FR on github, but I can open one if required.

Thanks,

Brian.