Calculate difference in dates

[Dr John Stockton]

JRS: In article <[email protected]>, dated
Tue, 7 Sep 2004 03:53:05, seen in Otter

I've looked high and low for a javascript counter which can break down
to years/month/days since an event happened but I have yet to find
one. I am assuming now that it can't be done otherwise I'm sure I
would have come across one by now. Found lots of unanswered requests
for the same by others.

Counting in Y M D is not all that meaningful, since months (and years,
and days) vary in length.

By using the newsgroup FAQ, you should have found one which counts in
days and hh:mm:ss until Xmas noon (js-date2.htm#RC); you should be able
to modify that to count up.

Likewise, you could have found js-date1.htm#DYMD, which gives the
difference between two dates in Y M D.

Note that, since months differ in length, with two dates D1 D2, the YMD
that D2 is after D1 does not necessarily match the YMD that D1 is before
D2, on reasonable definitions.

 

[Mick White]

Then you could also do:

return ((theHour - 1) % 12) + 1;

Yes, you could, but it would be wrong. What if theHour is 0 (zero)?


Mick

 

[John G Harris]

If "theHour" is 0, then it is "12" am, no?
Mick

<snip>

Or 12 pm if your reference point is the previous noon instead of the
next noon.

There is also the problem of 12 noon, which is neither before (ante) nor
after (post) noon.

Altogether, the 24 hour clock as the railways call it is a lot easier to
code.

John

 

[Lasse Reichstein Nielsen]

Lasse Reichstein Nielsen wrote:

Yes, you could, but it would be wrong. What if theHour is 0 (zero)?

Arh, bugger. I always forget that %12 can give results that are not
between 0 and 11. May whoever made that decission be forced to watch
Barney for 24 hours a day until he repents!

/L

 

[Mick White]

Dr John Stockton wrote:

Yields 0 1 2 12 1 2 11.

Use ((theHour + 11) % 12) + 1;

24:00 hrs?
Mick

 

[Dr John Stockton]

JRS: In article <5Lq%[email protected]>, dated
Tue, 7 Sep 2004 22:37:53, seen in Mick White

Dr John Stockton wrote:



24:00 hrs?

I think I could answer your question, if only I knew what it meant.

In context, theHour is a getHours value, hence an integer in 0..23.

<URL:http://www.merlyn.demon.co.uk/js-date9.htm#1224>.

 

[Mick White]

JRS: In article <5Lq%[email protected]>, dated
Tue, 7 Sep 2004 22:37:53, seen in Mick White



I think I could answer your question, if only I knew what it meant.

In context, theHour is a getHours value, hence an integer in 0..23.

<URL:http://www.merlyn.demon.co.uk/js-date9.htm#1224>.

OK, but I have seen "24:00" hours.
Mick