PHP---Date time

<code><span>//date函数，第二个参数取默认值的情况</span><span>echo</span> date(<span>"Y-m-d"</span>);<span>//2014-03-30</span><span>//date函数，第二个参数有值的情况</span><span>echo</span> date(<span>"Y-m-d"</span>,<span>'1396193923'</span>);<span>//2014-03-30,1396193923表示2014-03-30的unix时间戳</span></code>

<code><span>strtotime(<span>"2016-02-05"</span>)</span>;
<span>strtotime(<span>"2016-2-5"</span>)</span>; <span>//测试也可行</span></code>

<code><span>strtotime(<span>"now"</span>)</span>;

<span>strtotime(<span>"+1 seconds"</span>)</span>;

<span>strtotime(<span>"+1 day"</span>)</span>;

<span>strtotime(<span>"+1 week"</span>)</span>;

<span>strtotime(<span>"+1 week 3 days 7 hours 5 seconds"</span>)</span>;
</code>

<code><span>// gmdate() </span><span>//Y-m-d H:i:s</span><span>date_default_timezone_set(<span>"Asia/Shanghai"</span>)</span>;

echo <span>date(<span>'Y-m-d H:i:s'</span>, <span>time()</span>)</span>;

echo <span>gmdate(<span>'Y-m-d H:i:s'</span>, <span>time()</span>)</span>;</code>