The logo was named Google Doodle for the special day. Google is known for constantly adapting its logo for dates throughout the year, and this change to the Doodle, for the day definitely pushed the boundaries.
Using anniversaries like the 13th or your companies 21st birthday can be a very good way of promoting your corporate reputation of being in touch with your younger consumers. Celebrating birthdays that are big in their lives; 21st (becoming an adult) or 13th (becoming a teenager) can make your corporate anniversary seem more youthful and entertaining for younger customers.
If your company is not as big as Google, we suggest that utilizing a promotional product campaign to let consumers know about these different birthdays!