Date Comparison

cmiller · June 13th, 2003, 12:46 AM

Ok, this should be an easy one, though I don't know how.

Ok, I have a PHP generated date string, (you know that 10 or so number string that by itself means nothing to most of us), and I have another as well. What I want to do is compare the 2 strings and get the difference between them, i.e. hours, minutes, seconds, etc. Is this even possible? Or am I just crazy?

Thanks!

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~cmiller

Moharo · June 14th, 2003, 03:40 AM

ok so here's how you can do it. have something like

$dateold = date('Y-m-d')
$datenew = date('Y-m-d')

if you just want to compare these two just do split the time string

$dateoldArray = split("-",$dateold);
$datenewArray = split("-",$datenew);

you can subtract months for example

$monthdiff = $dateoldArray[1] - $datenewArray[2];

as of time (hours, seconds...) you can generate the string for example:

$timenow = "12:45:33";

then just repeat stuff as above. hope that helped

NotNowJohn · June 15th, 2003, 06:25 AM

If your dates are in the user friendly format (Y-m-d etc.)
you can use mktime function in order to change current format
to UNIX format. Newest value means number of seconds since 1.1.1970
and when you have two of these values you can easy subtract one from
the other and then convert second to H:m:s format.
Example:

Code:

function convert_this_date_to_unix_date($date)
{
    /*
    mktime func accept following params
    int hour, int minute, int second, int month, int day, int year
    and we have to explode $date value for the preparing for
    mktime func's usage
    */
    $date_sections=explode(" ", $date);
    $date_section=explode("-", $date_sections[0]);
    $time_section=explode(":", $date_sections[1]);
    $am_pm=($date_sections[2]=="PM")?12:0;

    return mktime ($time_section[0]+$am_pm, $time_section[1], $time_section[2],
            $date_section[1], $date_section[2], $date_section[0]);
}

$date1="2003-05-05 10:12:23 PM"
$date2="2003-05-06 11:12:23 PM"

//mktime

$date1_unix=convert_this_date_to_unix_date($date1);
$date2_unix=convert_this_date_to_unix_date($date2);
$diff=$date2_unix-$date1_unix;
$diff_in_hourminutesecond_format=date('H:i:s',$diff);

HTH.
Regs,
NotNowJohn

...but the Soon is eclipsed by the Moon

nikolai · June 19th, 2003, 02:58 PM

Is all the exploding above really necessary?? Why not just use strtotime()?

Code:

<?php

function date_diff($date_1, $date_2, $format = '')
{
   $ts = abs(strtotime($date_1) - strtotime($date_2));

   return ($format == '')? ts : date($format, $ts);
}

The optional parameter, $format, lets you choose between returning a formatted date string and a unix timestamp.

Take care,

Nik
http://www.bigaction.org/