Clock Cipher
Encode and decode using clock positions. Letters correspond to hour positions on a clock face.
e.g., 1 2 3* (use * for inner ring)
Clock Reference (12-hour)
A
M
B
N
C
O
D
P
E
Q
F
R
G
S
H
T
I
U
J
V
K
W
L
X
Y
Z
Puzzle Tips
- • Look for clock images or time references in puzzles
- • Multiple clocks might spell out a message
- • Hand positions indicate the letter
- • Some variants use only the hour hand
What is the Clock Cipher?
The Clock cipher encodes letters using positions on a clock face. Each hour position corresponds to one or more letters. There are several variants of this cipher.
Common Variants
12-Hour with Inner/Outer Rings
Uses two concentric rings on the clock face:
- Outer ring: A-L at positions 1-12
- Inner ring: M-X at positions 1-12
- Center: Y and Z
Hour:Minute Format
Uses the minute hand position to distinguish letter pairs:
- :00 minutes: A-L (first half of alphabet)
- :30 minutes: M-X (second half)
Clock Cipher in Geocaching
This cipher is popular in puzzles because:
- Visual: Clocks make great puzzle images
- Time themes: Historical or time-related caches
- Multiple clocks: Each clock shows one letter
- Field puzzles: Can use real sundials or clocks
Recognizing Clock Ciphers
Look for these clues:
- Images of clocks with hand positions
- Times listed in a specific pattern
- References to "time" or "hours"
- Exactly 12 or 24 items/values