At least here in Germany, December 1st. marks the start of the SOTA Winter bonus period. This period can be different on an association by association basis but I think those summits that are high enough to be applicable for the bonus points in Central Europe start tomorrow.
Remember the fact that if you already activated a particular qualifying summit this year - if it wasn’t activated in the early 2018 Winter Bonus period can earn you just the “missing” winter bonus points (3) in this Winter Bonus period up until the end of December. From january 1st it can be activated again for it’s normal points (plus Winter Bonus points).