Snow on the Tissington Trail

I did some signing at Ashbourne yesterday, checked the alignment of Route 68 and noted the access points of the Tissington Trail between Ashbourne and Parsley Hay, for the Sustrans online mapping. It was a beautiful sunny day. At the northern end of the trail I found snow still lying in the sheltered spots. How long ago did it snow? I hear that more is forecast for the coming weekend.