Converting a Total Time to Seconds

Question

I'm totalling up time like so.

$totalTimeDiff = new DateTime("@0");
foreach($dbrecords as $row)
{
    $timeDiff = date_diff( ... two datetimes from my database ... )
    $totalTimeDiff->add($timeDiff);
}

So $totalTimeDiff is a DateTime object with the sum of all of the time differences added together (so a sum of all of the durations). How can I get the total time in seconds?

1. use `DateInterval`, as you are calculating a proper interval and not storing a date; 2. read its documentation in order to get your interval in seconds. — moonwave99, Jan 29 '14 at 02:04
If I use date_diff to get a difference, how can I convert that to seconds? I didn't see that in the documentation. I just see how to retrieve the seconds from there. — muttley91, Jan 29 '14 at 02:24
[Just compute the difference with _now_](http://stackoverflow.com/questions/3176609/calculate-total-seconds-in-php-dateinterval). — moonwave99, Jan 29 '14 at 10:40

score 0 · Answer 1 · answered Jan 29 '14 at 02:04

0

Why not keep it simple?

$totalseconds=0;
foreach($dbrecords as $row)
  $totalseconds+=(UNIX_TIMESTAMP(second_datetime)-UNIX_TIMESTAMP(first_datetime));

answered Jan 29 '14 at 02:04

Eugen Rieck

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This will work as long as the values in the database are saved with respect to UTC. If storing local values (hopefully not), then you have to take time zones and DST into account, which is much more difficult. – Matt Johnson-Pint Jan 29 '14 at 02:27
Since we calculate the difference, the time offset will delta out as long as both have the same. – Eugen Rieck Jan 29 '14 at 02:29
True, but they might not necessarily be the same if one value is before a transition and the other is after. – Matt Johnson-Pint Jan 29 '14 at 02:30
If this is the case, then a lot of things will break: End time might be before start time – Eugen Rieck Jan 29 '14 at 02:31
In addition to that, the UNIX_TIMESTAMP() function will rebase to UTC. – Eugen Rieck Jan 29 '14 at 02:32

score 0 · Answer 2 · answered Jan 29 '14 at 02:45

0

use strtotime function

echo strtotime('01:00:00') - strtotime('TODAY');

answered Jan 29 '14 at 02:45

Shinto Joseph

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score 0 · Answer 3 · answered Jan 29 '14 at 03:00

0

$totalTimeDiff->format('U');

answered Jan 29 '14 at 03:00

evalarezo

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score 0 · Answer 4 · answered Jan 29 '14 at 17:30

Taking moonwave99's advice, I used DateInterval (can't remember why I went with DateTime for that in the first place, possibly a workaround for something at another stage of the project) and computed the seconds by adding each value to the total after converting it to seconds (converting hours and minutes to seconds and summing them up). I did this by using the DateInterval class's seconds property as well as the following function to convert a DateInterval to seconds (Note: only accounted for days, hours, minutes, and seconds for my specific case as there's no chance the amount will exceed one month):

function convertDateIntervalToSeconds($dateInterval)
{
    $days = $dateInterval->d * 24 * 60 * 60;
    $hours = $dateInterval->h * 60 * 60;
    $minutes = $dateInterval->i * 60;
    $seconds = $dateInterval->s;

    return $hours + $minutes + $seconds;
}

Converting a Total Time to Seconds

4 Answers4