가장 편리한 방법
echo strtotime('23:59:59')-time();
가장 빠른 방법
$now = time();
echo 86400-date('H', $now)*3600- date('i', $now)*60-date('s');
더 빠른 방법
echo 86400-(time()+8*3600)%86400;
테스트 데이터 포함
xubanditdeMacBook-Pro:~ xubandit$ time php -f a.php
real 0m31.146s
user 0m30.966s
sys 0m0.075s
xubanditdeMacBook-Pro:~ xubandit$ time php -f b.php
real 0m48.574s
user 0m48.329s
sys 0m0.098s
xubanditdeMacBook-Pro:~ xubandit$ time php -f c.php
real 0m11.156s
user 0m10.786s
sys 0m0.098s
xubanditdeMacBook-Pro:~ xubandit$ cat a.php
<?php
for($i=0;$i<10000000;$i++){
strtotime('23:59:59')-time();
}
xubanditdeMacBook-Pro:~ xubandit$ cat b.php
<?php
for($i=0;$i<10000000;$i++){
$now = time();
86400-date('H', $now)*3600- date('i', $now)*60-date('s');
}
xubanditdeMacBook-Pro:~ xubandit$ cat c.php
<?php
for($i=0;$i<10000000;$i++){
86400-(time()+8*3600)%86400;
}