Japanese stationery shop icco nico has created the Harukoyomi (sticking calendar), a very clever line of printed masking tape that can be used to turn any notebook or piece of plain paper into an organized calendar. Other tape products coordinate with the set to effectively plot helpful bullet points to remind oneself of important tasks for the next 4.5 years.
(translated) If you paste a month’s worth, it is 18.5 centimeters from 1 to 31.
And the total length of this mast is 10 m = 1000 cm.
1000 ÷ 18.5 = about 54
is 54 ÷ 12 = 4.5 in four years half.
via Spoon & Tamago