[Young Werther]

I graduated from high school on one of rare play dough days when the number is the same when viewed upside down.

1961

[oh8eleven]

I was around back then too and still remember this ...

[Fiji Hill]

I graduated from high school on one of rare play dough days when the number is the same when viewed upside down: 1961

You'll have to wait until 6009 to do that again.

[dr_lew]

This made the cover of MAD magazine, IIRC. Last upside-down year ‘til 6009 !