Without having to maintain a list of NTP servers which use leap second smearing, and those which don't, is there a way to tell, just by looking at the response from an NTP server, whether leap-second smearing will be applied or not?
I think I can be sure about this for any timeX.google.com
time server, but since Google proposes their smearing as a standard, I imagine many other time servers might follow suit.
I know from what I've read that the LI field will always be zero when smearing is used. I suppose that if I simultaneously consulted a different NTP server that I could be certain did NOT using smearing, then I'd know smearing would happen when the LI values differed. A more straight-forward test would be desirable, however.
Ideally this would be a flag that would be passed on by any NTP server which is itself synced to a Google NTP server, or other leap-second smearing server.