I'm not going to dive into a history lesson here. This is about practical, usable information in today's modern world. You can always go read more about GMT and UTC on Wikipedia.
- What is the difference between UTC and GMT?
- Really? There is no difference?
Technically, UTC is defined precisely (based on TAI + leap seconds), while GMT is not defined with such precision.
- So, GMT doesn't have leap seconds?
That's not what I said, and that's a common misconception. Both UTC and GMT have leap seconds.
- Well then, why would I use one over the other?
Most of the time, you should use UTC. However, if you're referring to the time zone segment that is used in the United Kingdom during the winter months, then use GMT. Just like US Eastern Time uses EST in the winter and EDT in the summer, the UK uses GMT in the winter and BST in the summer. (BST = British Summer Time)
- Are there any other contexts where it is appropriate to use GMT instead of UTC?
- What about in non-computing contexts? I hear GMT used on the radio all the time!
You were probably listening to the BBC. In general, the British tend to use GMT even in contexts where UTC would be more appropriate. There's nothing wrong with that. It's likely a matter of pride and tradition. It's a lot like sticking with imperial units of measure while those around you are on the metric system. Though in this case, the units are interchangeable.
- So when I see a time zone with an offset of GMT+2, that's wrong?
Yes. Well, at least I think so. People will probably understand you, but it's more correct to state it as UTC+02:00. And now, you know.
'GMT Standard Time' = UK Time (which will be GMT+0 in the winter or GMT+1 if it's the summer in the UK.) Basically if you want to convert UTC to UK time, use 'GMT Standard Time' Plain old 'GMT' (or Greenwich Mean Time) is more or less UTC, give or take a few milliseconds. Xampp php 5.3 download. Although GMT and UTC share the same current time in practice, there is a basic difference between the two: GMT is a time zone officially used in some European and African countries. The time can be displayed using both the 24-hour format (0 - 24) or the 12-hour format (1 - 12 am/pm).
Gmt Time Zone Map
- The primary difference remains to be the fact that GMT is the denomination of a timezone, while UTC is the title of the time standard. Where the technologies get involved? The advancement of telecommunication technologies influenced the creation of an even more precise system of time identification.
- Nowadays, Greenwich Mean Time, abbreviated as GMT, is a time zone designation rather than a time standard. Time difference between time zones can be expressed by the GMT or UTC offset. In the UTC standard, there is a commitment to keep within 0.9 seconds of GMT, so that every few years a leap second is applied to UTC.