从日期上减去一定的时间、天数、月份或年。

I'm trying to create a simple function which returns me a date with a certain number of subtracted days from now, so something like this but I dont know the date classes well:

我试着创建一个简单的函数，它给我一个日期，从现在开始，有一定数量的减去的天数，所以像这样，但我不知道日期类:

<?
function get_offset_hours ($hours) {
    return date ("Y-m-d H:i:s", strtotime (date ("Y-m-d H:i:s") /*and now?*/));
}

function get_offset_days ($days) {
    return date ("Y-m-d H:i:s", strtotime (date ("Y-m-d H:i:s") /*and now?*/));
}

function get_offset_months ($months) {
    return date ("Y-m-d H:i:s", strtotime (date ("Y-m-d H:i:s") /*and now?*/));
}

function get_offset_years ($years) {
    return date ("Y-m-d H:i:s", strtotime (date ("Y-m-d H:i:s") + $years));
}

print get_offset_years (-30);
?>

Is it possible to do something similar to this? this kind of function works for years, but how to do the same with other time types?

有可能做类似的事情吗?这种功能可以使用多年，但是如何在其他时间类型中使用呢?

3 个解决方案

#1

For hours:

几个小时:

function get_offset_hours($hours)
{
    return date('Y-m-d H:i:s', time() + 3600 * $hours);
}

Something like that will work well for hours and days (use 86400 for days), but for months and year it's a bit trickier...

类似这样的事情会持续好几个小时(使用86400天)，但几个月和一年就有点棘手了……

Also you can also do it this way:

你也可以这样做:

$date = strtotime(date('Y-m-d H:i:s') . ' +1 day');
$date = strtotime(date('Y-m-d H:i:s') . ' +1 week');
$date = strtotime(date('Y-m-d H:i:s') . ' +2 weeks');
$date = strtotime(date('Y-m-d H:i:s') . ' +1 month');
$date = strtotime(date('Y-m-d H:i:s') . ' +30 days');
$date = strtotime(date('Y-m-d H:i:s') . ' +1 year');

echo(date('Y-m-d H:i:s', $date));

#2

Try to use datetime::sub

尝试使用datetime::子

Example from the docs (linked):

示例来自文档(链接):

<?php

$date = new DateTime("18-July-2008 16:30:30");
echo $date->format("d-m-Y H:i:s").'<br />';

date_sub($date, new DateInterval("P5D"));
echo '<br />'.$date->format("d-m-Y").' : 5 Days';

date_sub($date, new DateInterval("P5Y5M5D"));
echo '<br />'.$date->format("d-m-Y").' : 5 Days, 5 Months, 5 Years';

date_sub($date, new DateInterval("P5YT5H"));
echo '<br />'.$date->format("d-m-Y H:i:s").' : 5 Years, 5 Hours';

?>

#3

something like this:

是这样的:

function offset hours($hours) {
    return strtotime("+$hours hours");
}