Get previous month value in PHP - php

I have used the below PHP function to get the previous month,
$currmonth = date('m', strtotime('-1 month'));
It was working fine and I was getting the value of 04 till yesterday. On today May 31st (Last day of the month May), I noticed the function returns the current month only. That is 05. Is there any other alternate function which returns the previous month accurately.

Try strtotime("first day of last month").
The first day of is the important part as detailed here.

Literally ask strtotime for the 'first day of the previous month' this makes sure it selects the correct month:-
$currmonth = date("m", strtotime("first day of previous month"));

You can use OOP with DateTime class and modify method:
$now = new DateTime();
$previousMonth = $now->modify('first day of previous month');
echo $previousMonth->format('m');

strtotime() works accurately. The problem is what you ask it to return.
"-1 month" is not the same as "previous month". It is the same as "subtract 1 from current month then normalize the result".
On 2017-05-31, subtracting 1 from current month gets 2017-04-31 which is not a valid date. After normalization, it becomes 2017-05-01, hence the result you get.
There are more than one way to get the value you need. For example:
// Today
$now = new DateTime('now');
// Create a date interval string to go back to the first day of the previous month
$int = sprintf('P1M%dD', $now->format('j')-1);
// Get the first day of the previous month as DateTime
$fdopm = $now->sub(new DateInterval($int));
// Verify it works
echo($fdopm->format('Y-m-d'));
// On 2017-05-31 it should print:
// 2017-04-01

If you just need to get the month number of previous month, the following should suffice.
$m = idate("m") - 1;
// wrap to previous year
if ($m < 1) {
$m = 12 - abs($m) % 12;
}
This works with arbitrary number of subtracted months.

Related

Getting first day of the month, is outputting the wrong first day of the month

I want to display the first day of the month in 'day of the week' format.
For example, The below code should select the month of August and say the day of the week 01 falls on which is Thursday, but for some reason, the below code outputs Friday which is wrong, on some months such as May it correctly says Wednesday.
$monthNumber = 3;
$base = strtotime(date('Y-m',time()) . '-01 00:00:01');
$dateTest = date("Ym" . 1, strtotime($monthNumber . " month", $base));
$unixTimestamp = strtotime($dateTest, $base);
echo date("l", $unixTimestamp);
Does anyone have any ideas to make it show the correct day?
$base fixes a bug with it not showing the correct month.
And why won't you use the dateTime?
echo (new \DateTime('first day of august 2019'))->format('l');
Read more about Relative formats.
You have to use date() at first:
$base = date('Y-m',time()) . '-01 00:00:00';
And dont have to set the first second :)
To get the day of the week falling on the first day of any month you can use the prefix first day of e.g.
echo (new \DateTime('first day of August'))->format('l');
This will show correctly Thursday for August 2019.
If you want to do it dynamically using numbers for months, you can create a dummy date like you were trying to do.
$timeString = sprintf('01.%02d.%04d', 8, 2019); // replace the numbers with your variables
echo (new \DateTime($timeString))->format('l');

Calculate date of last day of month before a target date

I can add any number of months to a date:
strtotime("+ 1 months", '2017-01-31') // result: 2017-03-03
But I want to do this without going to the next month.
in this case I want the result 2017-02-28, that is, the last day of the month before the target month.
There seems to be a lot of overcomplicating in these answers. You want the last day of the month before your target month, which is also always going to be 1 day before the first day of the target month. This can be expressed quite simply:
$months = 1;
$relativeto = '2017-01-31';
echo date(
'Y-m-d',
strtotime(
'-1 day',
strtotime(
date(
'Y-m-01',
strtotime("+ $months months", strtotime($relativeto))
)
)
)
);
Try using the DateTime object like so:
$dateTime = new \DateTime('2017-01-31');
$dateTime->add(new \DateInterval('P1M'));
$result = $dateTime->format('Y-m-d');
Use PHP's DateTime to accomplish this, specifically the modify() method.
$date = new DateTime('2006-12-12');
$date->modify('+1 month');
echo $date->format('Y-m-d');
If the idea here is not to allow the date to overflow into the next month, which PHP does, then you'll have to impose that constraint in your logic.
One approach is to check the modified month against the given month before returning the updated date.
function nextMonth(DateTimeImmutable $date) {
$nextMonth = $date->add(new DateInterval("P1M"));
$diff = $nextMonth->diff($date);
if ($diff->d > 0) {
$nextMonth = $nextMonth->sub(new DateInterval("P{$diff->d}D"));
}
return $nextMonth;
}
$date = new DateTimeImmutable("2017-01-31");
$nextMonth = nextMonth($date);
echo "{$date->format('Y-m-d')} - {$nextMonth->format('Y-m-d')}\n";
//2017-01-31 - 2017-02-28
$date = new DateTimeImmutable("2017-10-31");
$nextMonth = nextMonth($date);
echo "{$date->format('Y-m-d')} - {$nextMonth->format('Y-m-d')}\n";
//2017-10-31 - 2017-11-30
The nextMonth() function in the example above, imposes the constraint of not overflowing into the next month. Note that what PHP actually does is try to find the corresponding day, in the following consecutive number of months added, not just add a given number of months to the existing date. I simply undo this last part by subtracting any additional days beyond the 1 month interval in the function above.
So for example, strtotime("+1 month") for the date "2017-01-31", tells PHP find the 31st day that is +1 month from "2017-01-31". But of course, there are only 28 days in February, so PHP goes into March and counts up 3 more days to compensate.
In other words, it's not just add +1 month to this date, but add +1 month to this date and arrive at the same day of the month as is in the given date. Which is where the overflow happens.
Update
Since you've now made it clear that you actually want the last day of the month (not necessarily the same day of the next month without the overflow provision) you should instead just explicitly set the day of the month.
function nextMonth(DateTimeImmutable $date) {
$nextMonth = $date->setDate($date->format('Y'), $date->format('n') + 1, 1);
$nextMonth = $date->setDate($nextMonth->format('Y'), $nextMonth->format('n'), $nextMonth->format('t'));
return $nextMonth;
}
$date = new DateTimeImmutable("2017-02-28");
$nextMonth = nextMonth($date);
echo "{$date->format('Y-m-d')} - {$nextMonth->format('Y-m-d')}\n";
// 2017-02-28 - 2017-03-31

PHP strotime check + 10days to the first day of the next month

I need to check if the end of the month is within 10 days. If not, the date should be the first day of the following month. If the end of the month is within the next ten days, then I need to display first day of the month following next month.
Here is my code:
$tenDays = date('Y-m-d', strtotime('+10 days'));
$firstDayNextMonth = date('Y-m-d', strtotime('$tenDays, first day of next month'));
echo"$tenDays";
echo "<br>";
echo "$firstDayNextMonth";
The output is:
2015-08-01
1970-01-01
Based on the date today 2015-07-22 the desired outcome for the second line should be 2015-09-01, not 1970-01-01.
Stop using strtotime() for date math. That's not what it is there for. Use DateTime().
$firstDayNextMonth = (new DateTime('+10 days'))->modify('first day of next month')->format('Y-m-d');
Demo
Use 00 as the day-of-month:
$foo = new DateTime('2015-03-00');
$foo->format('r');
As you can see, the 0th of March, is the last day of February. So a simple $foo->format('d') will get you that last-day-of-month.

Date offset in PHP

I am doing my own calendar. For changing to the next and previous months, I use this function:
date('m',"-1 months");
date('m',"+1 months");
but, when I go to the next month, I can't use this again because -1 and +1 are always taken from now().
Assuming that I can't use dynamic numbers to that offset, I mean
date('m',"$x months");
how can I add or subtract 1 month to a specific date?
For example this date...
$date_today = strtotime($_GET['date']);
$next_month = $date_today +/- 1 month ?!?!??!
$next_month = strtotime('+1 month',$date_today);
Use strtotime...
$next_month = strtotime("+1 month");
Will give you a unix timestamp which you can pass to date...
echo date("m", $next_month);
I currently run a calendar for multiple sites with the same issue. I end up storing the current viewable month as a $_SESSION variable or pass it as a $_POST object when someone clicks on next or prev month.
When you would call it when the next or prev was hit a second time would (or the first time) would be something like
if(!isset($_SESSION['viewablemonth']) && $_SESSION['viewablemonth'] = '') {
$_SESSION['viewablemonth'] = date("m.d.Y");
}
End then do your month addition or subtraction:
$_SESSION['viewablemonth'] = strtotime("+1 month", $_SESSION['viewablemonth']);
You can mix strtotimes up with a reference date so:
$next_month=strtotime("+1 month"); // assumes today
$following_month=strtotime("+1 month", $next_month);
http://uk.php.net/manual/en/function.strtotime.php
Takes two parameters and assumes second parameter is time() current timestamp if ommitted

How to get previous month and year relative to today, using strtotime and date?

I need to get previous month and year, relative to current date.
However, see following example.
// Today is 2011-03-30
echo date('Y-m-d', strtotime('last month'));
// Output:
2011-03-02
This behavior is understandable (to a certain point), due to different number of days in february and march, and code in example above is what I need, but works only 100% correctly for between 1st and 28th of each month.
So, how to get last month AND year (think of date("Y-m")) in the most elegant manner as possible, which works for every day of the year? Optimal solution will be based on strtotime argument parsing.
Update. To clarify requirements a bit.
I have a piece of code that gets some statistics of last couple of months, but I first show stats from last month, and then load other months when needed. That's intended purpose. So, during THIS month, I want to find out which month-year should I pull in order to load PREVIOUS month stats.
I also have a code that is timezone-aware (not really important right now), and that accepts strtotime-compatible string as input (to initialize internal date), and then allows date/time to be adjusted, also using strtotime-compatible strings.
I know it can be done with few conditionals and basic math, but that's really messy, compared to this, for example (if it worked correctly, of course):
echo tz::date('last month')->format('Y-d')
So, I ONLY need previous month and year, in a strtotime-compatible fashion.
Answer (thanks, #dnagirl):
// Today is 2011-03-30
echo date('Y-m-d', strtotime('first day of last month')); // Output: 2011-02-01
Have a look at the DateTime class. It should do the calculations correctly and the date formats are compatible with strttotime. Something like:
$datestring='2011-03-30 first day of last month';
$dt=date_create($datestring);
echo $dt->format('Y-m'); //2011-02
if the day itself doesn't matter do this:
echo date('Y-m-d', strtotime(date('Y-m')." -1 month"));
I found an answer as I had the same issue today which is a 31st. It's not a bug in php as some would suggest, but is the expected functionality (in some since). According to this post what strtotime actually does is set the month back by one and does not modify the number of days. So in the event of today, May 31st, it's looking for April-31st which is an invalid date. So it then takes April 30 an then adds 1 day past it and yields May 1st.
In your example 2011-03-30, it would go back one month to February 30th, which is invalid since February only has 28 days. It then takes difference of those days (30-28 = 2) and then moves two days past February 28th which is March 2nd.
As others have pointed out, the best way to get "last month" is to add in either "first day of" or "last day of" using either strtotime or the DateTime object:
// Today being 2012-05-31
//All the following return 2012-04-30
echo date('Y-m-d', strtotime("last day of -1 month"));
echo date('Y-m-d', strtotime("last day of last month"));
echo date_create("last day of -1 month")->format('Y-m-d');
// All the following return 2012-04-01
echo date('Y-m-d', strtotime("first day of -1 month"));
echo date('Y-m-d', strtotime("first day of last month"));
echo date_create("first day of -1 month")->format('Y-m-d');
So using these it's possible to create a date range if your making a query etc.
If you want the previous year and month relative to a specific date and have DateTime available then you can do this:
$d = new \DateTimeImmutable('2013-01-01', new \DateTimeZone('UTC'));
$firstDay = $d->modify('first day of previous month');
$year = $firstDay->format('Y'); //2012
$month = $firstDay->format('m'); //12
date('Y-m', strtotime('first day of last month'));
strtotime have second timestamp parameter that make the first parameter relative to second parameter. So you can do this:
date('Y-m', strtotime('-1 month', time()))
if i understand the question correctly you just want last month and the year it is in:
<?php
$month = date('m');
$year = date('Y');
$last_month = $month-1%12;
echo ($last_month==0?($year-1):$year)."-".($last_month==0?'12':$last_month);
?>
Here is the example: http://codepad.org/c99nVKG8
ehh, its not a bug as one person mentioned. that is the expected behavior as the number of days in a month is often different. The easiest way to get the previous month using strtotime would probably be to use -1 month from the first of this month.
$date_string = date('Y-m', strtotime('-1 month', strtotime(date('Y-m-01'))));
I think you've found a bug in the strtotime function. Whenever I have to work around this, I always find myself doing math on the month/year values. Try something like this:
$LastMonth = (date('n') - 1) % 12;
$Year = date('Y') - !$LastMonth;
date("m-Y", strtotime("-1 months"));
would solve this
Perhaps slightly more long winded than you want, but i've used more code than maybe nescessary in order for it to be more readable.
That said, it comes out with the same result as you are getting - what is it you want/expect it to come out with?
//Today is whenever I want it to be.
$today = mktime(0,0,0,3,31,2011);
$hour = date("H",$today);
$minute = date("i",$today);
$second = date("s",$today);
$month = date("m",$today);
$day = date("d",$today);
$year = date("Y",$today);
echo "Today: ".date('Y-m-d', $today)."<br/>";
echo "Recalulated: ".date("Y-m-d",mktime($hour,$minute,$second,$month-1,$day,$year));
If you just want the month and year, then just set the day to be '01' rather than taking 'todays' day:
$day = 1;
That should give you what you need. You can just set the hour, minute and second to zero as well as you aren't interested in using those.
date("Y-m",mktime(0,0,0,$month-1,1,$year);
Cuts it down quite a bit ;-)
This is because the previous month has less days than the current month. I've fixed this by first checking if the previous month has less days that the current and changing the calculation based on it.
If it has less days get the last day of -1 month else get the current day -1 month:
if (date('d') > date('d', strtotime('last day of -1 month')))
{
$first_end = date('Y-m-d', strtotime('last day of -1 month'));
}
else
{
$first_end = date('Y-m-d', strtotime('-1 month'));
}
If a DateTime solution is acceptable this snippet returns the year of last month and month of last month avoiding the possible trap when you run this in January.
function fn_LastMonthYearNumber()
{
$now = new DateTime();
$lastMonth = $now->sub(new DateInterval('P1M'));
$lm= $lastMonth->format('m');
$ly= $lastMonth->format('Y');
return array($lm,$ly);
}
//return timestamp, use to format month, year as per requirement
function getMonthYear($beforeMonth = '') {
if($beforeMonth !="" && $beforeMonth >= 1) {
$date = date('Y')."-".date('m')."-15";
$timestamp_before = strtotime( $date . ' -'.$beforeMonth.' month' );
return $timestamp_before;
} else {
$time= time();
return $time;
}
}
//call function
$month_year = date("Y-m",getMonthYear(1));// last month before current month
$month_year = date("Y-m",getMonthYear(2)); // second last month before current month
function getOnemonthBefore($date){
$day = intval(date("t", strtotime("$date")));//get the last day of the month
$month_date = date("y-m-d",strtotime("$date -$day days"));//get the day 1 month before
return $month_date;
}
The resulting date is dependent to the number of days the input month is consist of. If input month is february (28 days), 28 days before february 5 is january 8. If input is may 17, 31 days before is april 16. Likewise, if input is may 31, resulting date will be april 30.
NOTE: the input takes complete date ('y-m-d') and outputs ('y-m-d') you can modify this code to suit your needs.

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