Quickly find the weekday to any date between 1500 and 2299.
You will receive a perpetual Gregorian calendar, covering the years from 1500 - 2299, which is printed on one self-adhesive label of size 2.25" x 4" (54 mm x 100 mm). Below the calendar table are the instructions in three lines of text. If you do not need the instructions simply cut them off.
The sticker fits nicely on a case for a deck of playing cards, with the instruction portion bent over the lower edge. (See the photo.) Thus, the calendar fits without the instructions on the back of a poker-size playing card. The calendar without instructions is small enough to fit on a standard sized business card (3.5" x 2"; 89 mm x 51 mm). For this you will have to trim the white borders of the label. There are many possible places for this sticker, in a book, notebook, planner, on the back of a business card, etc.
The numbers are small, but readable. I need my glasses to read them. If you do have bad eyesight it might not be readable for you. However, you will additionally get the calendar printed on a letter sized sheet of paper.
It is pretty amazing that 800 years can be covered without moving parts in such a small area.