Hi Matthew,
Thanks for letting me know. You may want to look into the date partition configuration. I also just want to confirm when you navigate to a different month, it still shows December as the first column. To protect your corporate data, I'm unable to really dig in and look into your environment. I would suggest submitting a support ticket or reaching out to your Customer Success Manager as next steps.
Thank you and best of luck,
Jessica
#ApptioforAll