The world unique time
Two things are important in an appointment for all participants: when & where? Nowadays, the "where" can be a real location (e.g. "Berlin, Alexanderplatz") or a conference call, a video conference, a chat room, a computer game and much more. All location terms are mostly unambiguous and understandable worldwide.
... By Markus Fleschutz 📅 April 27, 2019
At the "When " it is so far unfortunately less clear and understandable: you give only the local time in the regional notation. For example, at 10:20, the time zone is missing and people in the English-speaking world miss the indication "AM" or "PM". When determining the time zone, on the other hand, you always need the location and the date (for winter or summer time). Furthermore, with analog clocks, you can't tell whether it's morning or afternoon.
But with only two small steps one could make the time indication worldwide unambiguous:
Step 1: the 24-h-format
The 12-hour format with "AM" and "PM" is not clear especially at midnight and noon (0:00 AM or 0:00 PM? 12:00 AM or 12:00 PM?) and needs then an addition. In contrast, the 24-hour format is always unambiguous (0:00 to 23:59) and also more space-saving.
Step 2: the time zone abbreviation
Our earth is generally divided into 24 time zones, whereby a time zone comprises 15 degrees of longitude (24 × 15° = 360°). For each of these time zones, an abbreviation is now assigned as follows:
- Z stands as before for UTC (Coordinated Universal Time), also called Greenwich Mean Time or Zulu Time. Small letters stand for time zones with negative hour difference to UTC (UTC - x) Capital letters stand for time zones with positive hour difference to UTC (UTC + x) country domains for special time zones in Iran (ir), Afghanistan (af), India (in), Sri Lanka (lk)
This results in the following time zone abbreviations:
- l = UTC - 12 (Baker Island or Howland Island)
- k = UTC - 11
- j = UTC - 10 (Honolulu or Papeete)
- i = UTC - 9 (winter time in Anchorage)
- h = UTC - 8 (winter time in Los Angeles, Vancouver, Tijuana)
- g = UTC - 7 (winter time in Denver, Calgary)
- f** = UTC - 6 (winter time in Chicago, Mexico City, Havana)
- e = UTC - 5 (winter time in New York, Toronto, Havana)
- d = UTC - 4
- c = UTC - 3 (São Paulo, Buenos Aires or Montevideo)
- b = UTC - 2 (winter time in Nuuk)
- a = UTC - 1 (Praia)
- Z = UTC + 0 (winter time in London, Dublin, Lisbon)
- A = UTC + 1 (winter time in Berlin, Rome, Paris, Madrid, Warsaw)
- B = UTC + 2 (Cairo, Johannesburg, Kaliningrad)
- C = UTC + 3 (Moscow, Istanbul, Baghdad, Nairobi)
- D = UTC + 4
- E = UTC + 5
- F = UTC + 6
- G = UTC + 7 (Jakarta, Bangkok, Ho Chi Minh City)
- H = UTC + 8 (Shanghai, Beijing, Hong Kong, Singapore, Perth, Manila)
- I = UTC + 9
- J = UTC + 10 (Brisbane, Port Moresby, Vladivostok)
- K = UTC + 11
- L = UTC + 12 (winter time in Auckland, Suva)
- M = UTC + 13
- N = UTC + 14 (Kiribati)
For example, in summer time you live in time zone M and in winter time in time zone L. An advantage of the time zone abbreviation is that you can easily determine time zone differences: 'time zone D - time zone A = 4 - 1 = 3 hours difference'. The time zone abbreviation is simply appended to the 24-hour clock time and the time is unique worldwide.
Possibilities of the time indication
- 10:30:00A (long form with seconds)
- 10:30:00.123A (ultra long form with milliseconds)
- 10:30A (short form without seconds).
- 10½A (ultra-short form, to the nearest quarter of an hour, NEW).
- Mo10½A (ultra-short form with day of the week).
- 0:30Z means 00:30 AM in UTC+0 time zone.
- 11:30:00A means 11:30:00 AM UTC+1 (Central European Winter Time).
- 9a stands for 09:00 AM UTC-1.
- 8½J is the ultra-short form of 08:30 AM UTC + 10h.
- Appointment 20B@Berlin,Alexanderplatz means 8:00 PM UTC+2 in Berlin at Alexanderplatz.
- Who has an appointment at 9L and lives in time zone M, then this corresponds to 8M (the time zone difference is subtracted from the hour).