This is a three-dimensional nonogram. The first ten squares depict the layers of a $10\times10\times10$ cube. The final square gives the enumerations for the Z-axis, top to bottom. Some rules:
- If a row or column has no numbers, that means that the composition of that row/column is unknown. Note that this is different than the usual practice in nonograms where a missing number means that the row/column has no shaded cells at all. In our case, such rows can be explicitly marked with a zero.
- The Z-axis enumerations are all single digits, so e.g. 11 means two stretches of one, not one stretch of eleven.
- The thin black lines in the middle are just visual aids. They're not meaningful to the puzzle itself.
What day is it?