Convertng from 24 hours to 12 hour clock quickly.

Browsing through neowin I found a thread with poll asking whether one likes 12 hour system OR 24 hour system,and if so is that because it due to difficulty to convert it etc..Reading through the post I got a good tip..it is an easy way to convert between 24 to 12 hours quickly.Here is how:

Take the 24 hour time…. take 2 off it. Simple

13 — 3 - 2 = 1pm
14 — 4 - 2 = 2pm
15 — 5 - 2 = 3pm
16 — 6 - 2 = 4pm
17 — 7 - 2 = 5pm
18 — 8 - 2 = 6pm
19 — 9 - 2 = 7pm
20 — 10-2 = 8pm
21 — 11-2 = 9pm
22 — 12-2 = 10pm
23 — 13-2 = 11pm
00 — If ya can’t work that one out, don’t bother with 24hrs :-p