Is it stupid starting diet so close to Christmas?

Logging and tracking doesn't mean restricting calories - perhaps just adding food to your diary will make you more mindful about what and how much you're eating?

I’d say anytime is the perfect time to start being aware!! It all begins with it, right?

Have a lovely birthday. Maybe set MFP to maintenance based on your height, weight etc and then start cutting properly after Christmas. If you get into the habit of logging now it will be easier to keep going once you start cutting the calories. Just my twopence worth!

Just start making better choices and ask yourself if you REALLY want something that badly before you eat/drink it. Small steps.

If you have no intention of or ability to limit your intake over this time period then no I don't think you should start a "diet" right now. You are just going to beat yourself up for no reason.
You might figure out your maintenance calories and try making logging and maintaining your current weight a holiday challenge.
Or just wait until January for weight loss and work on mental health and liking yourself no matter what your weight right now.

I started mine in early November knowing it would be hard around the holidays, but instead of waiting, I went for it and have lost 8 pounds. Have I been perfect each and every day? No. Have I at least tried? Yes. Do I beat myself up if I indulge and have one meal that I know I could have made a better choice on? No. I enjoy it and move on. I watch the calories in, and I try to add more activity to my days to help offset when I splurge on something a little less healthy. Set some goals, make a plan for how to help achieve them, and then do what needs to be done, realizing every day is a new day and one day off the diet is not going to undo weeks of effort.

I always think it's a good idea to start logging your normal food intake for a while first to see where you can reduce calories without making drastic changes, no reason to go overkill on the run up to New Year but as has been mentioned already it can be worthwhile just so you become more mindful.

I agree that it's sometimes useful to log what you normally eat for a week or two before going into weight-loss mode. You can see if there's anything you can work on, learn to weigh/measure/read nutrition labels, see what kinds of food keep you full, and generally just start forming a habit. Then you can take the information you gathered and work in a calorie reduction. It can be very eye-opening to see your normal eating habits, and it might just take a few small changes to your regular eating patterns put yourself in a deficit.
It might also help you maintain instead of gain through the season. Oh, I had hot cocoa and cookies already, I can probably save this slice of pie for tomorrow. Oh, I'm going to a big holiday party tonight, maybe I'll just have some soup and crackers for lunch.

However, if you're ready, you're ready. I lost my first 60 pounds with a start date of 3 weeks before Thanksgiving, and kept it up over a year before I went on a long maintenance break. I reduced calories through the whole holiday season and lost weight.

Either way, pick what seems right for you - you don't want to set yourself up for failure if you have a feeling you should wait until the holidays are over.