Spanish artist Oscar Diaz found a literal way to mark time: He designed a calendar that writes itself. The dates of each month are embossed as a connected series of numbers on a sheet of paper; when the first digit is inserted into a bottle of ink, capillary action draws up the fluid and informs each date in succession over the course of the month.
Diaz writes, “The ink colors are based on a spectrum, which relate to a ‘color temperature scale,’ each month having a color related to our perception of the weather on that month. The colors range from dark blue in December to three shades of green in spring or orange and red in the summer.