In reply to Pinkelephant: It's a winter round. 16 hrs or so in darkness, cold temps, some snow cover. And it's the fastest winter round ever. Superb effort.
There can never be a standard winter round, so talk of records should be tapered a bit in winter as there's no standard round, all you can do is run your round and record your time and conditions.
For example you can't compare JF's winter round with OS's, both incredible undertakings.
On a year of no or little snow cover, a full moon and a stable high I don't doubt a supported sub 24 round is possible.