GMT vs UTC Usage

[Scan125]

This is just a general question about how people feel about the usage of GMT vs UTC, or UTC vs GMT.

For those who are not sure what the difference is then very simply GMT is a time zone (as is GMT +/-n) and UTC is a time attributed to no zone. Appart from that 22:10:01 GMT is the same as 22:10:01 UTC and vica versa.

I ask because in my software I use both local time (this is your local time in your time zone - e.g. GMT +1) or GMT (your local time minus 1 hour). I also for user display purposes on any clocks or setting might display "GMT/UTC".

However in my software logs etc. I record times as how you chose e.g. local (maked as LCL in logs) or GMT (marked as GMT in logs).

Now the Military use UTC ( Zulu just to add confusion for some). However commercial broadcasts stations around the globe generally use GMT (also published in broadcast time schedules).

If you used my software and saw GMT would it upset you if you were a UTC fan?

Do you really care as GMT/UTC or UTC/GMT are as far as you are concerned the same?

Any new software that I write, especially if radio comms/similar related) I'll probably use UTC.

 

[letarotor]

This is just a general question about how people feel about the usage of GMT vs UTC, or UTC vs GMT.

For those who are not sure what the difference is then very simply GMT is a time zone (as is GMT +/-n) and UTC is a time attributed to no zone. Appart from that 22:10:01 GMT is the same as 22:10:01 UTC and vica versa.

I ask because in my software I use both local time (this is your local time in your time zone - e.g. GMT +1) or GMT (your local time minus 1 hour). I also for user display purposes on any clocks or setting might display "GMT/UTC".

However in my software logs etc. I record times as how you chose e.g. local (maked as LCL in logs) or GMT (marked as GMT in logs).

Now the Military use UTC ( Zulu just to add confusion for some). However commercial broadcasts stations around the globe generally use GMT (also published in broadcast time schedules).

If you used my software and saw GMT would it upset you if you were a UTC fan?

Do you really care as GMT/UTC or UTC/GMT are as far as you are concerned the same?

Any new software that I write, especially if radio comms/similar related) I'll probably use UTC.

I thought that Greenwich Mean Time and Universal Time Coordinated were the exact same, each with just a different name?

Brian
COMMSCAN

 

[Scan125]

I thought that Greenwich Mean Time and Universal Time Coordinated were the exact same, each with just a different name?

Brian
COMMSCAN

They are to the extent that the time is the same in both as detailed in my post. No conversion etc required.

Mind you so is "color" and "colour"

What we are talking about is I guess acceptance, adopting UTC as oppose to GMT, and more accepted common usage.

Give it another 10 years GMT may be no longer used/mentioned having been dethroned by UTC.

 

[letarotor]

They are to the extent that the time is the same in both as detailed in my post. No conversion etc required.

Mind you so is "color" and "colour"

What we are talking about is I guess acceptance, adopting UTC as oppose to GMT, and more accepted common usage.

Give it another 10 years GMT may be no longer used/mentioned having been dethroned by UTC.

Gotcha 😁

Brian
COMMSCAN

 

[ka3jjz]

Actually there is a small difference between the two - however it's only important in certain scientific fields such as Radio Astronomy. For us, they are virtually interchangeable

Mike

 

[chief21]

If you're old enough, you may remember when GMT was the commonly-accepted civilian term for what is now known as UTC. According to the NOAA website, the UTC designation (which refers to a time standard, as opposed to an actual time zone) was created in 1972. Over the years, UTC has become much more common across the civilian world, but the military continues to use the proword ZULU (abbreviated "Z") to represent UTC.

 

[eorange]

I personally prefer UTC. Modern systems which utilize multi region time zones normalize time as UTC (for example). UTC would likely resonate with most people.

 

[kb7gjy]

Just a thought, Make it so you can it available as a drop down menu. Give the user the choice.

My 2 cents (adjusted for inflation) lol

 

[rk911]

GMT vs UTC is a distinction without a difference. don't make this complicated.

 

[Scan125]

Just a thought, Make it so you can it available as a drop down menu. Give the user the choice.

My 2 cents (adjusted for inflation) lol

Yes this could be done.

After a day of analysing code is dead easy to do 80%+ of the code change. Last 20% is handling what happens with user logs, saved data and ini file settings and field conversions. (Hopefully without breaking anything).

What really hurts are all the screen images. My user manuals have screen shots and also explanation text that details the data in screen shots. So a simple screen change of GMT to UTC actually has massive knock on effects if the images and words are to be kept synchronised.

I probably dropped a clanger when I wrote Scan125 in using GMT. Scan125 code base was used in Scan75. Other fragments of "reuse" code in DriveR8. So I seriously self compromised my in multiple places.

This why I'm asking as to move to UTC in existing code is going to be a nightmare of a job so if there are no radical and many objections to GMT then all is best left alone.

 

[vagrant]

Hello Nick, one person here that uses your software and I am fine with GMT. There are other things in life that deserve your attention, but your concern is appreciated.

 

[bb911]

UTC. BTW, CUT (Coordinated Universal Time) was sought by English speakers. French speakers wanted TUC (Temps Universel Coordonné). So UTC is a compromise between the two.

 

[W7FDX]

They are to the extent that the time is the same in both as detailed in my post. No conversion etc required.

Mind you so is "color" and "colour"

What we are talking about is I guess acceptance, adopting UTC as oppose to GMT, and more accepted common usage.

Give it another 10 years GMT may be no longer used/mentioned having been dethroned by UTC.

I use UTC personally but it took me a while to get out of the habit of calling it ZULU, just spent too much time around government workers I guess lol.

 

[majoco]

IMHO it's more complicated than that. Greenwich observatory is right on the 000° meridian and it was based on the time of the passing of the sun over that meridian. However back in the 1930's (I believe) they found that the rotation of the earth was slowing based on the observation of the stars so they had to introduce a correction which why we now occasionally have 'leap seconds'. The time based on the stars is called "sidereal time" and when we all (?) went metric the Bureau of International Weights and Measures in Paris gave it the name 'Co-ordinated Universal Time'. There is a difference between GMT and UTC but to the general user it's insignificant when catching your bus in the morning.

Difference Between GMT and UTC | Compare the Difference Between Similar Terms

GMT vs UTC When it comes to time keeping, one should know that the time difference between GMT and UTC is a fraction of a second and, for most common pur

www.differencebetween.com

 

[n1das]

UTC. BTW, CUT (Coordinated Universal Time) was sought by English speakers. French speakers wanted TUC (Temps Universel Coordonné). So UTC is a compromise between the two.

Universal Time, Coordinated.

I like UTC.

 

[Scan125]

Universal Time, Coordinated.

I like UTC.

Yes I think we all like UTC but were you to use a program or web reference source that used GMT would you be pissed off?

 

[majoco]

No.

 

[a417]

Yes I think we all like UTC but were you to use a program or web reference source that used GMT would you be pissed off?

None of the server instances I maintain use GMT, both virtualized and hardware.

As BIOSes started to allow you to specify local system time in UTC, and most *nix systems I use (all, now that I think about it) now assume the system clock is UTC...writing a program that hardcodes into GMT seems like a bit of a kludge.

Calling UTC system time in code seems easier, and it makes logging easier for distant servers in different time zones.

 

[mmckenna]

Yes I think we all like UTC but were you to use a program or web reference source that used GMT would you be pissed off?

No. Understanding that they are ~essentially~ the same thing, most of us can translate that on our head. Like color versus colour. If someone or some program really relies on the difference between the two for scientific observations, I'd hope they'd have the appropriate tools to do it correctly.

And as others have pointed out, much better things to be concerned about, like why hot dogs come in packages of 10 and hot dog buns come in packages of 8.

 

[kc2kth]

I think the simpler answer that I haven’t seen mentioned here is that GMT is a time zone (that has been mentioned) while UTC is a time standard. GMT happens to have a +/- offset of 0 to the UTC standard, so we tend to think of them as equivalent.

- kc2kth