Foundations of Amateur Radio Right now it's 10:45. That piece of information is unhelpful without any context. I could just as easily have told you that it's 2:45 and it would be just as accurate, helpful and meaningless. The point being that without context, you don't know if I'm an insomniac, drinking morning tea, recovering from a late lunch or putting on my PJs. If I'm talking to people in the same room, supplying the time happens within the context of that room, but if the world is our oyster, our room is a little larger and dawn for one person is dusk for another, at the same time. Before we could communicate at the speed of light and travel faster than a bullet, time was a relative thing related to the location of the Sun and considered mainly by mariners and astronomers. Even with the advent of increasingly accurate clocks, for most people, noon was when the Sun was at its highest point and the local clock was set to that. When our world got smaller, because communication and travel got faster, people started noticing that noon in one place wasn't the same as noon in another place. It became a real problem when people travelled hundreds of kilometres by train in a day. Imagine coming up with a train time-table that takes into account each local version of noon. In an attempt to deal with this, railroad managers in the United States established 100 railroad time zones. This malarkey continued until the 18th of November 1883 when four standard time zones were established for the continental United States. Of course, being human and all, that was a local solution. Great Britain had already established its own standards for time for England, Scotland and Wales. In October 1884, the International Meridian Conference, held in Washington DC, adopted a proposal that designated the Prime Meridian for longitude and timekeeping should be the one that passes through the centre of the transit instrument at the Greenwich Observatory in the United Kingdom and established Greenwich Mean Time, or GMT as the world's time standard. Why Greenwich? At the time the United Kingdom had more ships and shipping using Greenwich as their reference than the rest of the world put together and the observatory at Greenwich had produced the highest quality data for a long time. As an aside, on a French map before 1911, 0 degrees was centred over Paris. There are other wrinkles, like the fact that Earth isn't round and as a result the Greenwich Prime Meridian is not quite in the right spot because measurements didn't take into account local variations in gravity. In 1972, Coordinated Universal Time, or UTC replaced GMT as the standard for time in the world. It now references the International Reference Meridian, currently about a 102.5m east of the original Prime Meridian passing through Greenwich. It's on the move with reference to land because tectonic plates shift and where it is today is not where it's going to be tomorrow, so don't go looking for a marker to indicate the IRM. Meanwhile in the rest of the world people needed to come to terms with how to standardise on what to call time zones. The USA establishing four time zones was just for one country. Depending on who's counting, there's over 200 countries and each has its own set of time zones. Which each might include daylight saving, or not. For some, like VK6, daylight saving was voted on several times. Trials were had and time changes during summer were implemented, then reversed, then reversed again, and again, in total, VK6 did this dance six times and we currently don't observe daylight saving, neither does VK4 or VK8. So, not only does 10:45 require location context, it also requires that you know if there's daylight saving happening at that time in that location, which to add insult to injury, doesn't actually happen on the same date each year. It gets better if you consider time in another location. Do they have daylight saving, is it on at the time, do we have daylight saving at that time, how many hours are we apart, when is this actual event and what if we're coordinating efforts between people in multiple locations? Did I mention that summer in Europe is in July and in Australia it's in January? In case you're wondering, tracking all this is a massive job currently under the purview of the Internet Assigned Numbers Authority. The person coordinating this, whilst wrangling the politics of naming things, including dealing with warring countries who take umbrage at having their time zone named after "the enemy" is computer scientist Paul Eggert, the project lead of the time zone database. War aside, time zones are political. For example, Dublin Time was stamped out by the British as punishment for the Easter Rising. If that wasn't exciting enough, to provide local context, we use abbreviations to indicate which location we're talking about. In VK6 that abbreviation is WST, simple enough, Western Standard Time. What if your abbreviation was CST? Is that Central Standard Time in North America, China Standard Time, Cuba Standard Time, or even Australian Central Standard Time. If your local time zone is IST, you could be referring to Indian Standard Time, Israel Standard time, Irish Standard Time or even Irish Summer Time. As radio amateurs we hold global contests and we advertise our online club meetings and events. Often, we refer to times and dates that might be understood by an audience of one, but utterly confusing to the rest of the world. So, what do you do with this? Simple, use UTC. My timezone, called WST, or AWST, is UTC+8. F-troop, a weekly net for new and returning amateurs runs every Saturday morning at midnight UTC, that's 0:00 UTC. No confusion, no daylight saving, everyone can figure out if it's worth being awake for and I must applaud the amateurs from G-land and PA with their contributions in the very, very early hours of their morning. So, next time you make some noise about a contest, or any amateur activity that goes beyond the people in your suburb, specify the time in UTC. Who knows, perhaps one day, even the likes of SpaceX, Apple and Google will start using UTC to announce their events ... As Goldie Hawn put it: "Well, in my time zone that's all the time I have, but maybe in your time zone I haven't finished yet. So stay tuned!" I'm Onno VK6FLAB