24 in about ten minutes. I bet I could crank out two or three more if I spent another half hour staring at it. I'm impatient though, so I'm about ready to start googling (cheating).
And no, it's not a "Month Calendar" on 33. Not really any measurement at all.
EDIT: Up to 26 now. Still can't get 10, 14, 17, and 28-31. I think they're supposed to get harder as they go, though 32 would belong in the first five.
Just got 19. I had 16, and then got one that led to a couple others.
For some reason 31 is bugging me. I feel like I'm close, but can't figure it out. I'm thinking it's some sort of game (chess, checkers, cards) and something per opponent. I don't know... I could be way off.
1 26 L of the A 26 letters of the alphabet
2 7 D of the W 7 days of the week
3 7 W of the W 7 wonders of the world
4 12 S of the Z 12 signs of the zodiac
5 66 B of the B 66 books of the bible
6 52 C in a P (WJs) 52 Cards in a pack (without jokers)
7 13 S in the USF 13 stripes in the united states flag
8 18 H on a G C 18 holes on a golf course
9 39 B of the O T 39 books of the old testament
10 5 T on a F 5 toes on a foot
11 90 D in a R A 90 degrees in a right angle
12 3 B M (S H T R) 3 blind mice (see how they run)
13 32 is the T in D F at which W F 32 is the temperature in degrees fahrenheit at which water freezes
14 15 P in a R T
15 players in a rugby team
15 3 W on a T 3 wheels on a tricycle
16 100 C in a R 100 cents in a rand
17 11 P in a F (S) T 11 players in a football (soccer) team
18 12 M in a Y 12 months in a year
19 13=UFS 13 is unlucky for some
20 8 T on a O 8 tentacles on a octopus
21 29 D in F in a L Y 29 days in february in a leap year
22 27 B in the N T 27 books in the new testament
23 365 D in a Y 365 days in a year
24 13 L in a B D 13 loaves in a bakers dozen
25 52 W in a Y 52 weeks in a year
26 9 L of a C 9 lives of a cat
27 60 M in a H 60 minutes in a hour
28 23 P of C in the H B 23 pairs of chromosomes in the human body
29 64 S on a C B 64 squares on a chess board
30 9 P in S A 9 provinces in south africa
31 6 B to an O in C 6 balls to an over in cricket
32 1000 Y in a M 1000 years in a millenium
33 15 M on a D M C 15 men on a dead mans chest