Only the last column is actually needed for figuring out the other dates; the middle column is given because people frequently want to know quickly what day of the week the first falls on. |
Computing dates takes only a little practice. If you need to know what day of the week the 24th of January falls on, you learn to break 24 down into three sevens plus three. The first is a Tuesday, so 1 plus 21 is a Tuesday. If the 22d is a Tuesday, the 24th must be a Thursday. |
Or: you know immediately from the last column that the 20th must be a Sunday (from the sequence 6, 13, 20, 27). Twenty plus four must be the same as Sunday plus four days, which is a Thursday. |
If this version is still too minimalist for your taste, you might prefer the "unreduced" format below. |