将 php 时间戳舍入到最接近的分钟

Question

Assuming I have a unix timestamp in PHP. How can I round my php timestamp to the nearest minute? Eg 16:45:00 as opposed to 16:45:34?

Thanks for your help! :)

Answer 1

If the timestamp is a Unix style timestamp, simply

$rounded = round($time/60)*60;

If it is the style you indicated, you can simply convert it to a Unix style timestamp and back

$rounded = date('H:i:s', round(strtotime('16:45:34')/60)*60);

round() is used as a simple way of ensuring it rounds to x for values between x - 0.5 <= x < x + 0.5 . If you always wanted to always round down (like indicated) you could use floor() or the modulo function

$rounded = floor($time/60)*60;
//or
$rounded = time() - time() % 60;

Answer 2

An alternative is this:

$t = time();
$t -= $t % 60;
echo $t;

I've read that each call to time() in PHP had to go all the way through the stack back to the OS. I don't know if this has been changed in 5.3+ or not? The above code reduces the calls to time()...

Benchmark code:

$ php -r '$s = microtime(TRUE); for ($i = 0; $i < 10000000; $i++); $t = time(); $t -= $t %60; $e = microtime(TRUE); echo $e - $s . "\n\n";'

$ php -r '$s = microtime(TRUE); for ($i = 0; $i < 10000000; $i++); $t = time() - time() % 60; $e = microtime(TRUE); echo $e - $s . "\n\n";'

$ php -r '$s = microtime(TRUE); for ($i = 0; $i < 10000000; $i++); $t = floor(time() / 60) * 60; $e = microtime(TRUE); echo $e - $s . "\n\n";'

Interestingly, over 10,000,000 itterations all three actually do the same time ;)

Answer 3

Ah dam. Beat me to it :)

This was my solution also.

<?php 
$round = ( round ( time() / 60 ) * 60 );

echo date('h:i:s A', $round );
?>

http://php.net/manual/en/function.time.php

Answer 4

Simply use the following :

$last_hour   = date('Y-m-d H:00:00') // to last hour;
$last_minute = date('Y-m-d H:i:00')  // to last minute;

I use it to delete old shopping carts with expiry date (+ 5 minutes grace) in my database :

// clean expired shopping carts
function shop_clean_carts($grace = 5) {
    
    $expiry = date('Y-m-d H:i:00', strtotime("-$grace minutes"));
    $q      = "DELETE FROM `shop__cart` 
               WHERE `expiry` < '$expiry'
               AND `expiry` IS NOT NULL
               AND `fk_order_id` IS NULL";
    $db->query($q);
    
    return;
}

This is better to mySql NOW() because the query will be cached.