上个月在 php 的约会

echo strtotime("-1 month");

That will output the timestamp for last month exactly. You don't need to reset anything afterwards. If you want it in an English format after that, you can use date() to format the timestamp, ie:

echo date("Y-m-d H:i:s",strtotime("-1 month"));

Oh I figured this out, please ignore unless you have the same problem i did in which case:

$prevmonth = date("M Y",mktime(0,0,0,date("m")-1,1,date("Y")));

$prevmonth = date('M Y', strtotime("last month"));

You can use strtotime, which is great in this kind of situations :

$timestamp = strtotime('-1 month');
var_dump(date('Y-m', $timestamp));

Will get you :

string '2009-11' (length=7)

It's simple to get last month date

echo date("Y-n-j", strtotime("first day of previous month"));
echo date("Y-n-j", strtotime("last day of previous month"));

at November 3 returns

2014-10-1
2014-10-31

Found this one wrong when the previous months is shorter than current.

echo date("Y-m-d H:i:s",strtotime("-1 month"));

Try on March the 30th and you will get 2012-03-01 instead of 2012-02...

Working out on better solution...

echo date('Y',strtotime("-1 year"));        //last year<br>
echo date('d',strtotime("-1 day"));     //last day<br>
echo date('m',strtotime("-1 month"));       //last month<br>

$time = mktime(0, 0, 0, date("m"),date("d")-date("t"), date("Y"));
$lastMonth = date("d-m-Y", $time);

OR

$lastMonth = date("m-Y", mktime() - 31*3600*24);

works on 30.03.2012

It works for me:

Today is: 31/03/2012

echo date("Y-m-d", strtotime(date('m', mktime() - 31*3600*24).'/01/'.date('Y').' 00:00:00')); // 2012-02-01
echo  date("Y-m-d", mktime() - 31*3600*24); // 2012-02-29

public function getLastMonth() {
$now = new DateTime();
$lastMonth = $now->sub(new DateInterval('P1M'));
return $lastMonth->format('Ym');
}

Use this short code to get previous month for any given date:

$tgl = '25 january 2012';


$prevmonth = date("M Y",mktime(0,0,0,date("m", strtotime($tgl))-1,1,date("Y", strtotime($tgl))));
echo $prevmonth;

The result is December 2011. Works on a month with shorter day with previous month.

if you want to get just previous month, then you can use as like following

$prevmonth = date('M Y', strtotime('-1 months'));

if you want to get same days of previous month, Then you can use as like following ..

$prevmonth = date('M Y d', strtotime('-1 months'));

if you want to get last date of previous month , Then you can use as like following ...

$prevmonth = date('M Y t', strtotime('-1 months'));

if you want to get first date of previous month , Then you can use as like following ...

$prevmonth = date('M Y 1', strtotime('-1 months'));

If you want to get first date of previous month , Then you can use as like following ... $prevmonth = date('M Y 1', strtotime('-1 months')); what? first date will always be 1 :D

This question is quite old but here goes anyway. If you're trying to get just the previous month and the day does not matter you can use this:

$date = '2014-01-03';


$dateTime = new DateTime($date);


$lastMonth = $dateTime->modify('-' . $dateTime->format('d') . ' days')->format('F Y');


echo $lastMonth; // 'December 2013'

$lastMonth = date('M Y', strtotime("-1 month"));
var_dump($lastMonth);
$lastMonth = date('M Y', mktime(0, 0, 0, date('m') - 1, 1, date('Y')));
var_dump($lastMonth);

Incorrect answers are:

$lastMonth = date('M Y', strtotime("-1 month"));
$lastDate = date('Y-m', strtotime('last month'));

The reason is if current month is 30+ days but previous month is 29 and less $lastMonth will be the same as current month.

e.g.

If $currentMonth = '30/03/2016';
echo $lastMonth = date('m-Y', strtotime("-1 month")); => 03-2016
echo $lastDate = date('Y-m', strtotime('last month')); => 2016-03

The correct answer will be:

echo date("m-Y", strtotime("first day of previous month")); => 02-2016
echo sprintf("%02d",date("m")-1) . date("-Y"); => 02-2016
echo date("m-Y",mktime(0,0,0,date("m")-1,1,date("Y"))); => 02-2016

The best solution I have found is this:

function subtracMonth($currentMonth, $monthsToSubtract){
$finalMonth = $currentMonth;
for($i=0;$i<$monthsToSubtract;$i++) {
$finalMonth--;
if ($finalMonth=='0'){
$finalMonth = '12';
}


}
return $finalMonth;


}

So if we are in 3(March) and we want to subtract 5 months that would be

subtractMonth(3,5);

which would give 10(October). If the year is also desired, one could do this:

function subtracMonth($currentMonth, $monthsToSubtract){
$finalMonth = $currentMonth;
$totalYearsToSubtract = 0;
for($i=0;$i<$monthsToSubtract;$i++) {
$finalMonth--;
if ($finalMonth=='0'){
$finalMonth = '12';
$totalYearsToSubtract++;
}


}
//Get $currentYear
//Calculate $finalYear = $currentYear - $totalYearsToSubtract
//Put resulting $finalMonth and $finalYear into an object as attributes
//Return the object


}

Simply get last month.

Example:

Today is: 2020-09-02

Code:

echo date('Y-m-d', strtotime(date('Y-m-d')." -1 month"));

Result:

2020-08-02