January 1. Not just another Saturday (like today). Not just another day on the calendar. Culture mandates that the day is special, a day for new beginnings. Sure, you can fight it, but I'd suggest that most entrepreneurs embrace the opportunity the day brings.
First, it gives you a chance to look back on the last year. Not checking out the best memes, the biggest tech stories or the worst CEO mistakes of the last year, but reviewing what you planned to do with your startup and what you actually did. Maybe you hit all your goals and you can drink another toast to your winner startup, but more likely, especially if you're in the early stages, you'd find you won some, lost some and ended up dealing with things you never saw coming. It is good to have a day when you can look back and think about what went right (or wrong) and what else needs to be done.
Which brings us to the second thing you'd do at the beginning of the new year. Make plans. Maybe even resolutions - make it a point to meet more people, get your expense reports done, get your team to learn how to brainstorm, post on your blog more regularly, remember to workout more often, try meditation. Presumably by now you've realized that resolutions are usually hard to keep unless there are plans to support them and preferably other people involved. So you start emailing your team, plotting time lines and reviewing each resolution to see if there's an app for that. So you've just transitioned from being thoughtful to determined.
And then, you notice that you're beginning to have new ideas - for your product/service, for a marketing campaign, for a new way to make money, whatever. The creative gears click when you look out at a year full of potential and start churning possibilities. You're no longer just determined, you're all energized and raring to go work on your ideas - you're excited about the new year.
No, it's not just another day on the calendar. Even if you're back to surfing for the best/worst lists. Happy New Year!