In a calendar month, a \(2 \times 2\) grid of dates is selected. Let the first date in the top-left corner be '\(a\)'. The dates in the grid can be denoted as: \(a\), \(a + 1\), \(a + 7\), \(a + 8\).
| \(a\) | \(a + 1\) |
| \(a + 7\) | \(a + 8\) |
1. The sum of the diagonals is
2. If the sum of the two diagonal pairs in such a \(2 \times 2\) grid is 34, then the sum of all dates is
3. If the sum of the two diagonal pairs in such a \(2 \times 2\) grid is 34, then the first date is
4. The date in the bottom-left corner is