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Question

How Many Seconds Between Two Dates?

Answer 1

+2 A:

create two Date objects and call valueOf() on both, then compare them.

JavaScript Date Object Reference

Jacob Relkin 2010-01-07 22:37:32

getSeconds() -> Returns the seconds. (Range is 0-59). Should be valueOf() or getTime()

steven 2010-01-07 22:44:36

Answer 2

+5 A:

I'm taking YYYY & ZZZZ to mean integer values which mean the year, MM & NN to mean integer values meaning the month of the year and DD & EE as integer values meaning the day of the month.

var t1 = new Date(YYYY, MM, DD, 0, 0, 0, 0)
var t1 = new Date(ZZZZ, NN, EE, 0, 0, 0, 0)
var dif = t1.getTime() - t2.getTime()

var Seconds_from_T1_to_T2 = dif / 1000;
var Seconds_Between_Dates = Math.abs(Seconds_from_T1_to_T2);

A handy source for future reference is the w3schools site

Alternatively, if your dates come in a format javascript can parse

var dif = Date.parse(MM + " " + DD + ", " YYYY) - Date.parse(NN + " " + EE + ", " +ZZZZ);

and then you can use that value as the difference in milliseconds (dif in both my examples has the same meaning)

Martin 2010-01-07 22:42:05

Exactly what I'm looking for.

steven 2010-01-07 22:45:36

Only the patterns used in the example aren't that right. 4-digit years is noted by lowercase `yyyy`, 2-digit months by uppercase `MM` and 2-digit days by lowercase `dd`.

BalusC 2010-01-07 22:49:20

I used the exact format in the question for clarity

Martin 2010-01-07 22:55:41

Martin, I have the impression that was not using any date patterns here. MM DD, YYYY and NN EE, ZZZZ are actually the "example values" that Steven asked. So in other words, he is not doing any kind for formatting.

Wagner Silveira 2010-01-07 23:25:49

I have updated the second example, which is what I guess everyone was getting confused about. I've also added a bit of clarification as to exactly how I'm interpreting the values given in his example.

Martin 2010-01-08 07:58:56

Answer 3

+1 A:

Just subtract:

var a = new Date();
alert("Wait a few seconds, then click OK");

var b = new Date();
var difference = (b - a) / 1000;

alert("You waited: " + difference + " seconds");

Seth 2010-01-07 22:43:54

Answer 4

+1 A:

var a = new Date("2010 jan 10"),
    b = new Date("2010 jan 9");

alert(
    a + "\n" + 
    b + "\n" +
    "Difference: " + ((+a - +b) / 1000)
);

Justin Johnson 2010-01-07 22:45:46

Answer 5

+1 A:

If one or both of your dates are in the future, then I'm afraid you're SOL if you want to-the-second accuracy. UTC time has leap seconds that aren't known until about 6 months before they happen, so any dates further out than that can be inaccurate by some number of seconds (and in practice, since people don't update their machines that often, you may find that any time in the future is off by some number of seconds).

This gives a good explanation of the theory of designing date/time libraries and why this is so: http://www.boost.org/doc/libs/1_41_0/doc/html/date_time/details.html#date_time.tradeoffs

rmeador 2010-01-07 22:58:46

+1 for mentioning the leap second issue! It's so frustrating when this gets mishandled, even by folks who ought to know better (POSIX committee, I'm lookin' at you...)

Jim Lewis 2010-01-07 23:44:37

Answer 6

A:

.Net provides the TimeSpan class to do the math for you.

var time1 = new Date(YYYY, MM, DD, 0, 0, 0, 0)
var time2 = new Date(ZZZZ, NN, EE, 0, 0, 0, 0)

Dim ts As TimeSpan = time2.Subtract(time1)

ts.TotalSeconds

Jeff.Crossett 2010-07-06 19:47:25

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How Many Seconds Between Two Dates?

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