time_since function displaying -1 year - php

Question

I have the following timestamp 1347216222 which is of day and am using it with a time_since function to check how long ago it was in hours.. minutes etc.
<?php
/* Works out the time since the entry post, takes a an argument in unix time (seconds) */
function time_since($original) {
// array of time period chunks
$chunks = array(
array(60 * 60 * 24 * 365 , 'year'),
array(60 * 60 * 24 * 30 , 'month'),
array(60 * 60 * 24 * 7, 'week'),
array(60 * 60 * 24 , 'day'),
array(60 * 60 , 'hour'),
array(60 , 'minute'),
);
$today = time(); /* Current unix time */
$since = $today - $original;
// $j saves performing the count function each time around the loop
for ($i = 0, $j = count($chunks); $i < $j; $i++) {
$seconds = $chunks[$i][0];
$name = $chunks[$i][1];
// finding the biggest chunk (if the chunk fits, break)
if (($count = floor($since / $seconds)) != 0) {
// DEBUG print "<!-- It's $name -->\n";
break;
}
}
$print = ($count == 1) ? '1 '.$name : "$count {$name}s";
if ($i + 1 < $j) {
// now getting the second item
$seconds2 = $chunks[$i + 1][0];
$name2 = $chunks[$i + 1][1];
// add second item if it's greater than 0
if (($count2 = floor(($since - ($seconds * $count)) / $seconds2)) != 0) {
$print .= ($count2 == 1) ? ', 1 '.$name2 : ", $count2 {$name2}s";
}
}
return $print;
}
echo time_since(1347216222);
?>
The output is -1 years, 12 months. Can anyone help me to fix this?

Answer 1

I tailored the function to use DateTime and DateInterval, which makes it more readable.
It differs from the function you posted with regard to how the time difference is treated. In your case, you tested the values twice (once for each "unit"). This required complex calculations on your part.
The function below, on the other hand, takes advantage of the fact that DateInterval gives you a ready-to-use difference in years, moths, days, hours, minutes and seconds (e.g. the difference between 2015 and 2014 is 1 year and 0 seconds, as opposed to UNIX timestamps). Furthermore, the usage of DateTime allows you to handle timezones gracefully.
That being said, all you need to care of is how to print that difference, and this is exactly what the for loops are for - we extract two values and use an extra item (we call such items guardians), to save additional conditions when we want to extract the second item.
Here's the function:
<?php
function pluralize($number, $unit) {
return $number . ' ' . $unit . ($number !== 1 ? 's' : '');
}
function time_since(DateTime $original) {
$now = new DateTime('now');
$diff = $now->diff($original);
//is from the past?
if ($diff->invert) {
$chunks = [
[$diff->y, 'year'],
[$diff->m, 'month'],
[$diff->d, 'day'],
[$diff->h, 'hour'],
[$diff->i, 'minute'],
[$diff->s, 'second'],
[0, 'guardian'],
];
for ($i = 0; $i < count($chunks) - 1; $i ++) {
list ($value, $unit) = $chunks[$i];
if ($value !== 0) {
$text = pluralize($value, $unit);
//append next unit as well, if it's available and nonzero
list ($nextValue, $nextUnit) = $chunks[$i + 1];
if ($nextValue !== 0) {
$text .= ' ' . pluralize($nextValue, $nextUnit);
}
return $text;
}
}
}
return 'just now';
}
And the tests:
echo time_since(new DateTime('2014-01-01')) . PHP_EOL;
echo time_since(new DateTime('2014-10-09')) . PHP_EOL;
echo time_since(new DateTime('2014-11-09')) . PHP_EOL;
echo time_since(new DateTime('2014-11-10')) . PHP_EOL;
echo time_since(new DateTime('2014-11-10 13:05')) . PHP_EOL;
echo time_since(new DateTime('2114-11-10 13:05')) . PHP_EOL; //future
Results:
rr-#work:~$ php test.php
10 months 9 days
1 month 1 day
1 day 13 hours
13 hours 5 minutes
38 seconds
just now