Is that -2 F or -2 C?
Silkies are still chickens so frequency and timing of lay will be like other chickens. Temperature has very little to do with it.
The primary impetus is daily light period. Or more accurately, whether the light period is increasing vis a vis daily dark period or vice versa.
If you are in the northern hemisphere and they all started laying in late November, they must be very young.
One winter a few years ago, I kept a daily log for four flocks. Each day I recorded daily high and daily low temperatures, precipitation (rain and snow), wind speed and egg production.
Our winter temps hang around teens F to 40 F but occasionally drop to zero or well below.
Through the entire winter there was no correlation between production and temperature.
As for time of day, do your chickens experience any light after dusk? Whether that be a heat lamp street lights, light from vehicles, outside light that shines into the coop?
It takes about 25 hours to produce an egg, so they will never lay at the same time every day even though it may seem like it because they won't lay at night unless they drop an egg from the roost. Otherwise, when that 25 hour cycle extends to after dusk, they'll hold that egg till morning. That also means, they will lay in the morning till the production cycle catches up with dawn. Then the eggs will come a little later every day till they skip a day.
That discussion refers to productive breeds like leghorns and RIRs. Silkies aren't known to be very productive so the production cycle and timing may not be as recognizable.