A question was raised internally how well we support leap seconds (https://ics-cert.us-cert.gov/sites/default/files/documents/Best_Practices_for_Leap_Second_Event_Occurring_on_31_December_2016_S508C.pdf)

We're looking at our respective platforms to see if they use smoothing to sneak the leap second in, or if 23:59:60 will be visible to applications. We use Poco for most of our time arithmetic -- have you considered leap seconds? Is there strict validation for seconds-per-minute ranges?

Thanks!