The source site for this is: http://www.google.com/holidaylogos.html

When it comes to Holidays, Google knows how to pass on the spirit. Their logos celebrate throughout the year with their design. If you are trying to get ideas to holiday-up your logo, there is a great place for inspiration, the google holiday logos gallery. You will find all their logos organized by year, starting from 1999. Check them out here.

Have A Happy New Year! Be Safe.