Rubik's Perpetual Calendar
Ideal Toy Co., 1981.
(plastic 2.2 inches, with cardboard can with plastic lid)
Rubik's 3x3x3 Cube
for which each day of the year one can solve the top face to that day.
It is much easier than the standard cube,
since only one side has to be solved.
For a given day,
the top left and bottom right corners of the top face are blank,
the top middle square has day,
the top left has one of Sun, Mon, Tues, Wednes, Thurs, Fri, Satur,
the middle three squares are the month,
JAN, FEB, MAR, APR, MAY, JUN, JUL, SEP, NOV, DEC,
and the bottom right two squares are the date (or just the bottom right if the date is only one digit).
Here is a Dutch version
Here is a Dutch version solved for Monday, Jan 1 on the left, and on the right the other three sides for this solution
Sunday through Saturday are
Zondag, Maandag, Dinsdag, Woensdag, Donderdag, Vrijdag, Zaterdag,
and January through December
are Januari, Februari, Maart, April, Mei, Juni,
Juli, Augustus, September, Oktober, November, December).