The last work week is usually the least productive for most people. You've eaten all you can eat. You're looking forward to New Year's Day. You just want to get through these next few days.
This week is traditionally very slow for a cleaning business. People's wallets are thinner and many people are still on vacation. That's why I make this week my thinking week.
What went wrong this year? How can those mistakes be corrected? What went right this year? What should I continue next year? All in all, I use this week as my assessment week.
You don't need to be a business to utilize "thinking week". Thinking week is for everyone; business, people, your job, even your car. Use the dead time to make next year more productive than this year.
Always be climbing the mountain or you'll start going down the mountain.