Is the Plummer Building about to turn 100 years old?

Dear Answer Man: I was downtown at the Plummer Building near the big brass doors and noticed something. The cornerstone for the building says 1927, therefore the Plummer Building will be officially 100 years old next year. Turns out, while the cornerstone was laid in 1927, the building wasn't officially opened until 1928, a year later, meaning the Plummer Building's centennial won't come until 2028. Still, Ziemer said, "Yes, Mayo Clinic is planning activities to commemorate the Plummer Building’s centennial in 2028, marking 100 years since the building officially opened. Beyond downtown is Dr. Donald C. Balfour House (1910), and, speaking of all things Plummer, Plummer House (1917-1924), plus many, many more.