# a.m. or am - punctuating time



## Thomas Tompion

In BE we used to write 9 a.m.  These days 9.00am seems to be much more common.  Is it now acceptable - or even proper practice - not to put the full stops and the space?


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## Trisia

I certainly hope not. Although I've used it myself...


*9 a.m.* strikes me as elegant. Any other option is probably quicker/more practical but not that comely.


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## sarcie

Informally, in SMS/e-mail for example, I leave the full stops out. 

Formally, in translations/customer mails, the full stops are a must - it looks so awkward without, I think. I agree with Trisia, I usually write 9 a.m. if it's on the hour, 9:15 a.m., etc.


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## Thomas Tompion

sarcie said:


> Informally, in SMS/e-mail for example, I leave the full stops out.
> 
> Formally, in translations/customer mails, the full stops are a must - it looks so awkward without, I think. I agree with Trisia, I usually write 9 a.m. if it's on the hour, 9:15 a.m., etc.


Hi, Sarcie.  Did you mean that colon?


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## panjandrum

Follow your style guide.
Most sizable organisations have standards for this kind of thing.
Here, generally, the tendency is to drop the full stops (sorry, periods) from abbreviations.  Hence I have been writing 9am, 9:30am and so on for so long that I have no idea when the transition took place if it ever did.  Similarly, I never put a . after abbreviated titles (my own is never abbreviated) so it's Dr Jekyll, Mr Hyde, Prof Moriarty etc.  And of course etc doesn't get a . either.

Times are part of the general pattern.


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## Trisia

Shall we start a different thread on clocks, watches*,* etc.? 

It's interesting that we only need to say 9 if it's on the hour, like Sarcie said. I mean, 9:00 a.m. is ok but doesn't seem really necessary.


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## panjandrum

Thomas Tompion said:


> Hi, Sarcie.  Did you mean that colon?


Overlap in posts, but I suspect Sarcie did mean to use the colon.  As you'll see, I used one as well.  I've no idea when that came in either.


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## sarcie

Thomas Tompion said:


> Hi, Sarcie.  Did you mean that colon?



Yes, and I stand by it . Might be a style preference, I've always written times with a colon.

Edit: Might also be my mixed education - I learned all my early English writing in a series of international schools, none of which followed a BE system. Therefore, I suspect it might be an AE thing, or alternatively a French thing.


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## Matching Mole

I think there has been a move to reduce this kind of punctuation over the last 50 years, certainly in the UK. If you look at business correspondence today compared to, say, the 50s, it's now virtually standard to drop all punctuation outside of the body of a letter (e.g. no commas after address lines, opening and closing, abbreviated forms of address, e.g. "Mr"). To my mind it looks much less cluttered and is easier to read. As previously mentioned, it's a style preference rather than an issue of absolute correctness.


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## river

Let's not forget that without the periods, AM stands for amplitude modulation broadcasting as compared with FM for frequency modulation broadcasting.


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## JamesM

Thomas Tompion said:


> Hi, Sarcie. Did you mean that colon?


 
The U.S. standard is to use a colon between hours, minutes, and seconds.


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## panjandrum

JamesM said:


> The U.S. standard is to use a colon between hours, minutes, and seconds.


I believe that is an ISO (International Organisation for Standardisation) standard.


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## LV4-26

Just scroll down to the bottom of your screen 


> All times are GMT +2. The time now is 12:49 AM.


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## JamesM

panjandrum said:


> I believe that is an ISO (International Organisation for Standardisation) standard.


 
The colons certainly are, but there's no provision in the ISO standard for a.m. or p.m., just 24-hour clocks, as far as I know.


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## Loob

I no longer use full stops in abbreviations such as am, pm, Mr, Mrs, MP.

Loob


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## panjandrum

JamesM said:


> The colons certainly are, but there's no provision in the ISO standard for a.m. or p.m., just 24-hour clocks, as far as I know.


Indeed not.  ISO would have no truck with anything so ambiguous.


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## bibliolept

No truck, indeed, with anything so truculent. Their system uses a very "modern" time format of *2007-07-20T15:51UTC*, for example, where the UTC signifies Universal Coordinated Time, with military time and the colon between the hours and minutes.


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## Packard

I think it is useful to make a distinction between symbols and abbreviations.

In the USA (a symbol) or U.S.A. (an abbreviation) we use "symbols" for the states in our mail addresses.

So New York is written NY as a symbol on letters, but N.Y. as an abbreviation in correspondence.

*ACE MANUFACTURING*
*123 South Street*
*New York, NY 12345*

*Dear Sirs,*

*We are looking for N.Y. manufacturers...*

Within the address portion, the "*NY*" is an official Postal *Symbol* and the periods are expressly left out.

Within the body of the letter, the "*N.Y.*" is an *abbreviation* and the periods are required.

Note:  All the states have state symbols, not just New York.  For example:  NJ, CA, NC, SC, ME, etc.  (no periods in any of them).


If you were compiling a table of high tide/low tide or a table of sunrise/sunset you could make a reasonable case for the position that the AM and PM are symbols within the chart.

Unlike the official Postal Symbols, I have never read of any "officially" designated symbols for AM/PM.

Other than that, I would use the abbreviation: a.m. and p.m.


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## sdgraham

_The Associated Press Stylebook_, used by most newspapers in the U.S., says, for example, it's 3:30 p.m. (for example)


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## Steubler

Back in public school in the 80s in the USA, we were taught to capitalize the letters of this abbreviation for "ante meridiem", with full stops, as in "9:00 A.M."  Of course, the same applies to the abbreviation "P.M." for  "post meridiem."


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## Packard

It seems that computerized automatic updates use "PM".



Publication of the National Oceanic & Atmospheric Administration (NOAA), U.S. Department of Commerce.
Last Updated: February 28, 2007 4:52 PM 


I would expect that given this proliferation that *AM *and* PM* will become accepted over time.


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## borritt

In the U.S., The Chicago Manual of Style is the gold standard for book publishing. The 14th Ed., 14.30, says the CMS preferred style is small caps with periods while British practice is lowercase with periods. However, they go on to say that small caps without periods is an acceptable alternative, and, if your system does not have small caps, full caps is acceptable. For British usage I would consult an authoritative style book, such as New Hart's Rules from OUP.
 It's always best to consult an authority rather than rely on a seat-of-the-pants "that looks dumb" guide.


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## sdgraham

borritt said:


> In the U.S., The Chicago Manual of Style is the gold standard for book publishing. The 14th Ed., 14.30, says the CMS preferred style is small caps with periods while British practice is lowercase with periods. However, they go on to say that small caps without periods is an acceptable alternative, and, if your system does not have small caps, full caps is acceptable. For British usage I would consult an authoritative style book, such as New Hart's Rules from OUP.
> It's always best to consult an authority rather than rely on a seat-of-the-pants "that looks dumb" guide.



Welcome to the list, Boritt.


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## Thomas Tompion

borritt said:


> In the U.S., The Chicago Manual of Style is the gold standard for book publishing. The 14th Ed., 14.30, says the CMS preferred style is small caps with periods while British practice is lowercase with periods. However, they go on to say that small caps without periods is an acceptable alternative, and, if your system does not have small caps, full caps is acceptable. For British usage I would consult an authoritative style book, such as New Hart's Rules from OUP.
> It's always best to consult an authority rather than rely on a seat-of-the-pants "that looks dumb" guide.


 
Welcome to the forum, Borritt, and thank you for your contribution.  I speak British English (BE) and would be grateful if you could say what precisely you mean by 'a seat-of-the-pants "that looks dumb" guide'.


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## Loob

The _Economist_, _Times_, and _Guardian_ style guides all show "am"/"pm" in lower case with no full stops.

Loob


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## borritt

Thomas Tompion said:


> Welcome to the forum, Borritt, and thank you for your contribution.  I speak British English (BE) and would be grateful if you could say what precisely you mean by 'a seat-of-the-pants "that looks dumb" guide'.



A poster who inquires about whether to write "8 A.M." or "8 AM" or anything else is appealing to authority. A reply that avers that something is just wrong strikes me as unhelpful. You know the saying, "Give a man a fish ..." 

So what is authority? Authority is whatever style guide your publisher or professor designates. If you're writing simply for yourself and don't care, then you can do anything you please. But in that case you would not be posting to a grammar site seeking guidance. So the best course is to follow one of the recognized guides. 

Style guides give consistency to a work, so that you treat "AM" the same on p. 39 as you did on p. 2. I think we've lost something by slavish devotion to consistency. Shaxpere could sign his name any one of a dozen ways and not be considered an ignoramus, but the fetish of the last couple of centuries has been rigid consistency. Without consistency a writer is no longer taken seriously.

 Of course, a guide is just that, a guide, and it must be applied with judgment. But whenever I have been challenged by an editor or writer, answering "I found it in Webster's" or "That's what Chicago recommends" carries far more weight than "I thought your way looked dumb."

Cheers!


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## Loob

borritt said:


> A poster who inquires about whether to write "8 A.M." or "8 AM" or anything else is appealing to authority.


 
Maybe, borritt. But he/she could equally well want to know what foreros do in "real life". 



> A reply that avers that something is just wrong strikes me as unhelpful.


Sure. But thankfully there are relatively few of those on WRF....

All the best, and let me add my welcome to the forums.

Loob


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## moonglow

<<moonglow's thread has been merged here>>

Depending on style, of course, which looks best to your eye? I know opinions will vary.

Space before 'pm'? Omit unnecessary ciphers?

a. 10pm
b. 10 pm
c. 10:00pm
d. 10:00 pm


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## morior_invictus

moonglow said:


> Depending on style, of course, which looks best to your eye? I know opinions will vary.
> 
> Space before 'pm'? Omit unnecessary ciphers?
> 
> a. 10pm
> b. 10 p*.*m*.*
> c. 10:00pm
> d. 10:00 p*.*m.


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## moonglow

In BrE punctuation?


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## entangledbank

Too many variations are possible to recommend any one as standing out. Personally I write 10 p.m., or 10.00 p.m. if the minutes are needed (note .00 not :00 for the divider). If you're writing ie and eg you'd naturally write am and pm, though they could still be spaced, 10 am and 10.00 pm. Probably if there are minutes you'd want to separate them from am/pm, thus 10.00 am not 10.00am, but I have to admit the latter is what we do at my workplace (style not very formal): 9am to 5.30pm.

The capitalized forms AM and PM are, I believe, largely AmE-only.


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## morior_invictus

Also in AmE, although I`ve seen A.M. and P.M. too, but always with periods between the letters and with the space between the number and the abbreviation.


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## PaulQ

a. 10pm
b. 10 pm
c. 10:00pm
d. 10:00 pm

All are OK, I can't get excited about the space between the number and 'pm'. You can add the full-stops if you want but I don't.

To me the purpose of the full-stops and space is to avoid confusion but I cannot see how 10am/10pm, etc could ever lead to confusion. 

It is worthwhile considering that 10am = "Ten hours of the clock in the forenoon" and given how much it has been compressed to arrive at 10am, even maximum compression does no harm.

However, perhaps I'm not the best person to answer; I use the 24-hour clock, so for 10:00pm I'd write 22:00 and for 10am, I'd write 10:00hrs.


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## temple09

If there is a fixed rule then I would say that the majority of people don't know it. Here is a quote from an official website which refers to time-zones and tries to clarify (regarding a slightly different subject) -
" TheTerms 12 a.m. and 12 p.m. cause confusion and should not be used as neither the "12 am" nor the "12 pm" designation is technically correct. It advisable to use 12 noon and 12 midnight where clarity is required. 
To avoid ambiguity, airlines, railroads, and insurance companies use 12:01am 
for an event beginning the day, 11:59pm for ending it."
Note that without specifically meaning to, the author has used a variety of options for the same thing.
Personally, I would write 10pm, 5.30pm, 9am. I don't normally specify the minutes either if it is on the hour (i.e. 10:00am is just 10am).If you want to avoid this then you could use the 24 hour clock, as long as it is clear that this is what you are doing, so 10pm could just be 22:00 (with the 24 hour clock you always need to specify the minutes)


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## Sparky Malarky

I've been told that some style guides (unfortunately, I can't tell you which) specify either 10:00 a.m. (note periods) or 10:00 AM (note no periods).  

I have never seen the period instead of colon used to designate time -- 10.30 instead of 10:30.  This must be a BrE vs. AmE difference.


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## JulianStuart

<<I have merged moonglow's question with a prior discussion.  There are responses above the last  7 or so threads that may help>>


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## ewie

temple09 said:


> If there is a fixed rule then I would say that the majority of people don't know it.


This thread amply illustrates that there is no fixed rule, so people can be forgiven for not knowing it

I'm fairly (52%) sure I never use a colon as divider, even with 24-hour clock ~ _9.25, 15.35_, etc.

As for _am, pm, a.m., p.m._, I do whatever my brain tells me at the time of writing


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## Loob

moonglow said:


> ... Space before 'pm'? Omit unnecessary ciphers?
> 
> a. 10pm
> b. 10 pm
> c. 10:00pm
> d. 10:00 pm


Looking specifically at moonglow's four options:
I'm pretty sure that I don't usually leave a space before *am/pm* - so I'd use (a) rather than (b).  I might put a space there on occasion, though.  

For "on the hour" times, I wouldn't normally add the '00'.  Unless I was using the 24-hour clock, I would use 10:XX (or 10.XX) only when XX was greater than zero.

(It's really strange to see things you posted 6 years ago coming back to haunt you!)


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## Rover_KE

Loob said:


> I no longer use full stops in abbreviations such as am, pm, Mr, Mrs, MP.
> 
> Loob



And like many other BE speakers, neither do I.

Rover


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## RM1(SS)

moonglow said:


> <<moonglow's thread has been merged here>>
> Depending on style, of course, which looks best to your eye? I know opinions will vary.
> 
> Space before 'pm'? Omit unnecessary ciphers?
> 
> a. 10pm
> b. 10 pm
> c. 10:00pm
> d. 10:00 pm



I would normally write this as "2200."  If I were for some reason using a twelve-hour clock, I would use your option 'b.'


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## natkretep

When I was in school (I left school in 1981), I wrote *10 p.m.* or *10.00 p.m.* By around the 1990s I left off the full stops (periods): *10 pm* or *10.00 pm*. Sometime after 2000, I left off the space: *10pm* or *10.00pm*. If I use the 24-hour clock, I write *22.00*.


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## moonglow

Curious. 

3:15 pm or 3:15pm ?

7:00 pm / 7:00pm / 7 pm / 7pm /  ?

I use the colon, not the full stop.


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## natkretep

I write 3.15pm and 7.00pm or 7pm. (5 years ago, I would have put in the space; 25 years ago, I would have put in the full stops.) But look at:
*a.m. or am - punctuating time*


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## JulianStuart

natkretep said:


> I write 3.15pm and 7.00pm or 7pm. (5 years ago, I would have put in the space; 25 years ago, I would have put in the full stops.) But look at:
> *a.m. or am - punctuating time*


Nice link.  The >6-year-old thread illustrates as well as describes the changes that have occurred, mainly in BrE recently.  I still usually put  a space between the number and the am or pm and , if I'm writing home, might still use the dots.  As with many other soft punctuation issues, there are variations and it only really matters when the text is going to a publisher that has a style guide for authors. Besides that, just be consistent and use a common format.


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## Wordsmyth

These days I nearly always write times in 24h clock format. I still sometimes use the 12h clock in speaking, but the punctuation doesn't often cause a problem there.
On the rare occasions when I write 12h clock times, I usually use _am_ and _pm_ without full stops — but I do remember an occasion where a colleague left a scribbled note for his secretary, giving his travel times. He'd written something like "Departing 1 am arriving midday". She couldn't make sense of it, because she read it as "Departing I am arriving ..."!


Sparky Malarky said:


> I have never seen the period instead of colon used to designate time -- 10.30 instead of 10:30.  This must be a BrE vs. AmE difference.


 I wouldn't say so. I've always used a colon (whether with 12h or 24h clock times), and a quick check of the websites of British Airways, National Rail (UK), Marks & Spencer and Tesco Stores shows that they all use the colon — and they all use the 24h clock, so the am/pm problem doesn't arise.

In my profession, we sometimes work with elapsed time, in h:min and in decimal hours; so a period of 10*:*30 is 10h 30min, whereas a period of 10*.*30 is 10h 18min. 

Ws


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## JamesM

I don't think the period is an American designation.    I've seen it before but it was not in anything from the U.S.


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## natkretep

My impression is that the colon is spreading in British use, possibly through the internet. When I grew up, I only remember seeing a dot used for time. I think British newspapers generally use the dot, though I note that the _Scotsman _used the colon when I lived in Scotland in the 1980s.

_The Times_ uses the dot in its stories, such as in this page from today:


> All the action here live as it happens with Charlie Byrne, from the Times fashion desk, commenting on the red carpet - then, later on, Oliver Moody will take over for the live ceremony
> 10.13pm: Done. What a terrific evening to be a bookmaker. <...>
> 10.10pm: And on that Demosthenic note, that’s pretty much your lot. <...>


(No space between the time and _pm_ and no full stops in _pm_)

However, a grey line of text announces:


> Last updated at 3:47PM, February 19 2014


That's a different style - with a colon, and with _pm_​ in capital letters (which strikes me as more American use). So that's one style for the body of the newspaper, and another on the online site for update information.


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## Flauterfiddle

Hello Word Reference Forum :=)

A fascinating and useful thread. My personal preference is 

9 a.m. (for whole hours)
9:30 p.m. (use of colon with half-hours, etc.)

I have also seen the dot "." used in German time formats instead of the colon. It's not standard there, either, so it's anyone's guess where that came from.

One other point, about retention/removal of dots for abbreviations. While some style guides rather go to town on removing dots wherever they find them -- the Guardian Style Guide (David Marsh) is a very good example -- the presence or absence of a dot after titles, such as "Mr", "Dr", etc. is not, apparently, the same thing.

In the case of times, such as "a.m.", the dot represents something left off the end, leaving the word incomplete. Thus, "a[nte] m[eridian]". Other Latin forms such as "e.g." also use the dot in this way: "e[xempli] g[ratia]". Or "etc.", which is properly "et c[etera]". In the case of titles, however, nothing is left off the end, it is left out of the middle of the word: "M[iste]r". Hence no dot in British English.

At least, that's the reasoning I've seen for most explanations of why titles do not have final dots in BrE. It is a peculiar little explanation, though.

Perhaps an American can now suggest why they do in fact use a dot -- I'm sure there's just as good as argument for them!

Thanks to all and I look forward to making the occasional post.

I've been lurking on the forum for a long time now :=)


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## Wordsmyth

Welcome to the forum, Flauterfiddle.

I've also come across that explanation of dots being used with truncated words and not with contractions where the missing bit is in the middle. I suppose it may have been standard practice at some time in the past, but it's certainly not systematic in current usage.

If it were, we'd still write_ B.B.C._ instead of _BBC_, and _U.K._ instead of _UK_ (and similarly for all other such initialisms). We'd also write _ad lib._, rather than _ad lib_, but I don't think I've ever seen that.

_By the way, it's "ante meridiem". (Sorry to jump on someone who's just come out of hiding after lurking for so long ) _

Ws


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## JulianStuart

Wordsmyth said:


> _By the way, it's "ante meridiem". (Sorry to jump on someone who's just come out of hiding after lurking for so long ) _
> 
> Ws



So you think since the word ends in an m and we have omitted everything from the front of the word, we should not use a dot,?  As in " 3:00 a. m "?


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## Smauler

Good god, people....

It's not, you know, complicated

I use 9am, 9:45am, 9am, 9:45pm to tell time.


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## JulianStuart

It's only complicated if you wish to convince someone you're right and they're wrong

So you use 9am twice  and why no :00 after the 9 for the hour?


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## Wordsmyth

JulianStuart said:


> So you think since the word ends in an m and we have omitted everything from the front of the word, we should not use a dot,?  As in " 3:00 a. m "?


  (I guess you had really noticed Flauter's 'typo'.)

However, that does remind me of a discussion I once read, between two 'purist' supporters of the theory that Flauter mentioned, about whether _Avenue_ should be abbreviated to _Ave._ or _Ave_ (since they couldn't decide whether the _e_ was the third or the last letter of _Avenue_)!

Ws


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## Bobby Treat

Thomas Tompion said:


> In BE we used to write 9 a.m.  These days 9.00am seems to be much more common.  Is it now acceptable - or even proper practice - not to put the full stops and the space?



I don't see any answers that address the practical issues. Suppose I want to enter a sentence like, "I saw no clocks, but 5 A.M. was a good guess." Word processors will incorrectly capitalize "Was", and there's often a merry little dance getting that corrected. That's just ONE example of the difficulties periods cause if they're not THE END OF A SENTENCE. There are also examples, like 500 BC, 89.5 FM, and PM Tony Blair, FBI, CIA, and hundreds of others, in which periods are not used to separate the letters of a acronym. As I see it, the purpose of grammar is to make things clear, not to make a writer's job difficult, and 5 AM is certainly just as clear as 5 A.M., without those unnecessary hassles.


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## ewie

Bobby Treat said:


> Word processors will incorrectly capitalize [...] and there's often a merry little dance getting [...] that corrected


The trick is to switch off your grammar/spellchecker ~ I won't have one in the house


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## sdgraham

Bobby Treat said:


> I don't see any answers that address the practical issues. Suppose I want to enter a sentence like, "I saw no clocks, but 5 A.M. was a good guess." Word processors will incorrectly capitalize "Was", and there's often a merry little dance getting that corrected. That's just ONE example of the difficulties periods cause *be*cause if they're not THE END OF A SENTENCE. There are also examples, like 500 BC, 89.5 FM, and PM Tony Blair, FBI, CIA, and hundreds of others, in which periods are not used to separate the letters of a acronym. As I see it, the purpose of grammar is to make things clear, not to make a writer's job difficult, and 5 AM is certainly just as clear as 5 A.M., without those unnecessary hassles.


First of all, the English language existed for a *very* long time before computers and I don't see that speakers are about to be enslaved by some minor bit of programming, especially, as Ewie says, it's so easy to turn off "auto-correct." (As I also do on all my devices)

As always, such issues are a matter of style, which can vary from one style guide to another. It's just a matter of picking one and sticking with it.

If one were to follow your logic, we'd just do away with upper-case letters entirely, since that would make things easier, no? (Morse Code, Telegrams, Teletypes, etc. never were case-sensitive and they were the basic form of telecommunication for years.

As a side note, FBI and CIA are initialisms and not acronyms, such as NATO, SHAPE, FIFA, etc.


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## SReynolds

I'd like to see the ISO date/time standard spread. I'm doubly biased, though, because I'm both Hungarian (we and east Asian countries have the most consistent date/time system) _and_ I work with IT systems all the time.

To me, the only logical way to write _August 12, 2013, 5:11pm _is: 2013-08-12 17:11. This is amazing, because it can be extended further, e.g. _2013-08-12 17:11:01.531_ can be used to specify an event with millisecond precision.


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## Wordsmyth

SReynolds said:


> This is amazing, because it can be extended further, e.g. _2013-08-12 17:11:01.531_ can be used to specify an event with millisecond precision.


... and that underlines the importance of the colon as an h:min:s separator, at least in some contexts, so that the point (dot) can be used for decimal times — be they decimal hours (as I mentioned back in post #45) or decimal seconds as in this case.

(PS. Can't wait for train departure times to be quoted as, say, 17:11:01.531 — just think of the opportunities for delays that that would open up!)

Ws


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## SReynolds

Not just for delays, imagine one train arriving at 17:11:01.531 at platform 2 and another departing at 17:11:01.831 from platform 3, meaning you would have exactly 0.3 of a second to alight and change trains.


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## Keith Bradford

panjandrum said:


> I believe that is an ISO (International Organisation for Standardisation) standard.




There certainly is: ISO 8601 which can be consulted on http://www.cl.cam.ac.uk/~mgk25/iso-time.html.


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## ewie

sdgraham said:


> As always, such issues are a matter of style, which can vary from one style guide to another. It's just a matter of picking one and sticking with it.


I hope you meant, Mr G, it's a matter of picking _one style_ and sticking with it, rather than picking _one style guide_ and sticking with it.
I've never followed a style guide in my life ~ well, not consciously, anyway.


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## Bobby Treat

sdgraham said:


> First of all, the English language existed for a *very* long time before computers and I don't see that speakers are about to be enslaved by some minor bit of programming, especially, as Ewie says, it's so easy to turn off "auto-correct." (As I also do on all my devices)
> 
> As always, such issues are a matter of style, which can vary from one style guide to another. It's just a matter of picking one and sticking with it.
> 
> If one were to follow your logic, we'd just do away with upper-case letters entirely, since that would make things easier, no? (Morse Code, Telegrams, Teletypes, etc. never were case-sensitive and they were the basic form of telecommunication for years.
> 
> As a side note, FBI and CIA are initialisms and not acronyms, such as NATO, SHAPE, FIFA, etc.



"Cause" was the right word above, not "because"; speakers have nothing to do with it, since we're talking about the printed word; and all those letter combinations are the very same thing -- the first letters of several words that make up the name of something.


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## Bobby Treat

But I can turn off auto-correct, on the other hand -- I don't have any problem with spelling. I just don't see any point in it.


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## Bobby Treat

Anyway ... I'll do as I please, so there was no good reason to ask the question.


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## Roymalika

Hi, 

Looking at the previous posts, it is clear that both "am/pm" (without dots) and "a.m./p.m." (with dots) are acceptable. But I wonder whether using a single dot (between *a* and *m* or after *m*) is also acceptable? I mean: a*.*m / p*.*m OR am*.* / pm*. *

Example sentence:
My chemistry class is at 8 a.m (or am.) tomorrow. I have to get to college in time.


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## sdgraham

Roymalika said:


> I mean: a*.*m / p*.*m OR am*.* / pm*. *


It's wrong according to any style book with which I'm familiar.


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## heypresto

Roymalika said:


> But I wonder whether using a single dot (between *a* and *m* or after *m*) is also acceptable?


Wonder no more. It's not acceptable.


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## Packard

At best, it would look like a typo.  Don’t use any periods or invest in two.


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