Why does everyone wait until New Years to start making life changes? Because it's a significant date. It's an easy place to purge your old self and start on your new "life model". You want to lose weight? January 1st you'll start that diet/exercise plan. You want to be a writer? January 1st, you'll write 30 minutes every day. New years, new life, new you... it's a great and natural marketing opportunity. Gym memberships soar in January.
Here's the thing: you can make any non-normal instance a "life model" purge.
Three years ago I changed my life around because I refused to use a CPAP machine in March.
Two years ago I changed my life again because I got engaged in February.
Last year my life changed in May, August, and September. Whirlwind year, and going to be hard to top.
My point is: if you've made a resolution for New Years, I hope you stick with it. Like I said in You Can Kaizen, it's all about small sustainable changes.
If you made a resolution for New Years and you fail, then I hope you find another event that kick-starts that life model purge.
Most importantly, I hope you don't give up entirely and just wait for another New Year to roll around. The book I linked above has 365 ways you can make each day a little "non-normal". Every day try to get back to what you really wanted on January 1st. You don't need the calendar to tell you when to change.