A time warp

Our Christmas cactus is now over 20 years old. In the summer of 2017 I read that they enjoy being outdoors during the summer months. So, out it went. Big mistake! It hated the experience and gave every indication of being on its death bed. So early this year I pruned it back to ground level. It loved that and is now flowering better than ever before. The only problem is that it has lost the track of time and is flowering in mid-November rather than at Christmas.