Around the World in 1 Day (Solution)

by Charles Steinhardt

Each image can be identified both as a specific location and to a specific time of day, either from a visible clock in the image or from context that can be determined by finding the image's source.

If the images were all taken in a 24-hour span in January, then taking time-zones into account they end up in the following order, beginning with midnight mass as indicated by the flavortext:

ImageCityTimeUTC+/- Military Timezone Designation
8 Vatican City 0:00 +1 A
17 Terceira ~23:00 -1 N
5 Chicago 19:15 -6 S
11 Kailua-Kona 15:51 -10 W
20 Dushanbe 8:45 +5 E
2 New York 23:15 -5 R
16 Brisbane ~15:15 +10 K
4 Melbourne ~17:15 +11 L
9 Tokyo 3:35 +9 I
3 Praia 7:25 -1 N
12 Chiang Rai 16:20 +7 G
6 Rio de Janeiro 7:25 -2 O
24 Ponta Delgada 10:30 -1 N
18 Rome 13:35 +1 A
22 Nauru (link) 1:00 +12M
15 Riga 15:45 +2 B
1 Paris ~16:00 +1 A
13 Milwaukee 9:20 -6 S
23 New Orleans 11:25 -6 S
21 Monte Carlo 19:00 +1 A
7 Moscow 23:20 +4 D
19 Sao Paulo 18:25 -2 O
10 Boston 15:46 -5 R
14 St. Louis 15:40 -6 S

The military timezone designations spell out ANSWER KLINGON AMBASSADORS.