This evening. Frost + security lighting = sparklies everywhere! 
Yay! I hope you're keeping warm, and enjoying the sparklies!
When I was 16, my family was living in Germany, and one night on one of our many touristy weekends, we went for a walk after our evening meal. We ended up walking by some Bavarian cottages, and everything had a substantial blanket of snow on, and the houses had lovely outdoor lighting... it was sparkly and magical, and I'll never forget it.