As MAD Magazine pointed out on its cover for the March 1961 issue, this was the first "upside-up" year — i.e., one in which the numerals that form the year look the same as when the numerals are rotated upside down, a strobogrammatic number — since 1881. The next such year will be 6009.

As MAD Magazine pointed out on its cover for the March 1961 issue, this was the first "upside-up" year — i.e., one in which the numerals that form the year look the same as when the numerals are rotated upside down, a strobogrammatic number — since 1881. The next such year will be 6009.