What is the origin of donating 67 minutes of your time to honor Nelson Mandela on his birthday on July 18?

1 Minute for Each Year

Nelson Mandela gave 67 years of his life to the struggle for social justice. Please give 67 minutes.

According to the official website of Nelson Mandela Day:

...all you have to do on July 18 is donate 67 minutes of your day to doing something good in any way you can. Nelson Mandela gave 67 years of his life to the struggle for social justice. Can you spare 67 minutes of yours to support a charity or serve your local community?

(See the Related link to the official website of Nelson Mandela Day.)