php Find the start of week 16 in 2010 - php

Ok so I want to get the Monday of week 16 in 2010 (more precisely to week $week of year $year). here is what I have in my test.php file
$week = 16;
$year = 2010;
$dateString = $dateString = 'Start of week ' . $week . ' in ' . $year;
$date = strtotime( $dateString );
echo $date;
The value returned is false. I have also tried using Monday of week... but this also gave a false result.
any idea how to get a date given a week number and the year?
thanks


I'd recommend using the builtin \DateTime class.
Inspired by the answer here I tested the following code:
<?php
function getStartDate($week, $year) {
$dto = new DateTime();
$dto->setISODate($year, $week);
return $dto->format('Y-m-d');
}
$week = 16;
$year = 2010;
var_dump(getStartDate($week, $year));
This returned the following:
/some/fancy/path/test.php:12:string '2010-04-19' (length=10)


Monday is the first day of the week. Make use of setISODate()
<?php
$gendate = new DateTime();
$gendate->setISODate(2022,2,1); //year , week num , day
echo $gendate->format('d-m-Y'); //"prints" 10-01-2022

Related

strtotime('-1 month') returning wrong date if month have 31 days

I'm trying make a function to return the exact date of previous months.
That is a example of my code:
// Dates in TimeStamp
$ts_now = strtotime('now');
$ts_month1 = strtotime("-1 month", $ts_now);
$ts_month2 = strtotime("-2 month", $ts_now);
$ts_month3 = strtotime("-3 month", $ts_now);
// Dates Formated
$date_now = date('Y-m-d', $ts_now);
$date_month1 = date('Y-m-d', $ts_month1);
$date_month2 = date('Y-m-d', $ts_month2);
$date_month3 = date('Y-m-d', $ts_month3);
//Output
echo $date_now; //2020-04-30
echo $date_month1; //2020-03-30
echo $date_month2; //2020-03-01
echo $date_month3; //2020-01-30
The problem is in $date_month2 that represents February, the output is 2020-03-01 instead 2020-02-29 and I suppose that problem will happen in months who have 30 days when present date have 31 days.
What is the best way to resolve that?

As you can see working with the end of the month can be problematic because of how PHP works with dates. Your best bet is to go back to the beginning of the month, do your date math (i.e. go backwards in time), and then go to the date you want. That way you can check to see if the current day is greater than the number of days in month. If so, use the last day of the month instead.
function getMonthsAgo(int $n): string {
$date = new DateTime();
$day = $date->format('j');
$date->modify('first day of this month')->modify('-' . $n . ' months');
if ($day > $date->format('t')) {
$day = $date->format('t');
}
$date->setDate($date->format('Y'), $date->format('m'), $day);
return $date->format('Y-m-d');
}
// Dates Formated
$date_now = date('Y-m-d');
$date_month1 = getMonthsAgo(1);
$date_month2 = getMonthsAgo(2);
$date_month3 = getMonthsAgo(3);
//Output
echo $date_now;
echo $date_month1;
echo $date_month2;
echo $date_month3;
Output:
2020-04-30
2020-03-30
2020-02-29
2020-01-30

Find date of after 2 months using php

When i have current date is in "31/12/2017". I need to find date of after 2 months that means its February. When its february i need to get as "29/2/2018". But When we use below code i got "03/03/2018". Can you please help me to solve this task,
Here i added my PHP code,
$xmasDay = new DateTime('2017-12-31 + 2 month');
echo $xmasDay->format('Y-m-d');

please try this
<?php
function add_month($date_str, $months)
{
$date = new DateTime($date_str);
// We extract the day of the month as $start_day
$start_day = $date->format('j');
// We add 1 month to the given date
$date->modify("+{$months} month");
// We extract the day of the month again so we can compare
$end_day = $date->format('j');
if ($start_day != $end_day)
{
// The day of the month isn't the same anymore, so we correct the date
$date->modify('last day of last month');
}
return $date->format('Y-m-d');
}
$result = add_month('2017-12-31', 2);
echo $result

calculate from first of the month, then use date t
$orginal = '2017-12-31';
$orginal = explode('-', $orginal);
$originalDate = strtotime($orginal[0] . '-' . $orginal[1] . '-01 00:00:00');
$newDate = strtotime('+2 month', $originalDate);
echo date('Y-m-t', $newDate);
// or
$date = new DateTime();
$date->setTimestamp($newDate);
echo $date->format('Y-m-t');

PHP subtract 1 month from date formatted with date ('m-Y')

I'm trying to subtract 1 month from a date.
$today = date('m-Y');
This gives: 08-2016
How can I subtract a month to get 07-2016?

<?php
echo $newdate = date("m-Y", strtotime("-1 months"));
output
07-2016

Warning! The above-mentioned examples won't work if call them at the end of a month.
<?php
$now = mktime(0, 0, 0, 10, 31, 2017);
echo date("m-Y", $now)."\n";
echo date("m-Y", strtotime("-1 months", $now))."\n";
will output:
10-2017
10-2017
The following example will produce the same result:
$date = new DateTime('2017-10-31 00:00:00');
echo $date->format('m-Y')."\n";
$date->modify('-1 month');
echo $date->format('m-Y')."\n";
Plenty of ways how to solve the issue can be found in another thread: PHP DateTime::modify adding and subtracting months

Try this,
$today = date('m-Y');
$newdate = date('m-Y', strtotime('-1 months', strtotime($today)));
echo $newdate;

Depending on your PHP version you can use DateTime object (introduced in PHP 5.2 if I remember correctly):
<?php
$today = new DateTime(); // This will create a DateTime object with the current date
$today->modify('-1 month');
You can pass another date to the constructor, it does not have to be the current date. More information: http://php.net/manual/en/datetime.modify.php

I used this to prevent the "last days of month"-error. I just use a second strtotime() to set the date to the first day of the month:
<?php
echo $newdate = date("m-Y", strtotime("-1 months", strtotime(date("Y-m")."-01")));

if(date("d") > 28){
$date = date("Y-m", strtotime("-".$loop." months -2 Day"));
} else {
$date = date("Y-m", strtotime("-".$loop." months"));
}

$lastMonth = date('Y-m', strtotime('-1 MONTH'));

First change the date format m-Y to Y-m
$date = $_POST('date'); // Post month
or
$date = date('m-Y'); // currrent month
$date_txt = date_create_from_format('m-Y', $date);
$change_format = date_format($date_txt, 'Y-m');
This code minus 1 month to the given date
$final_date = new DateTime($change_format);
$final_date->modify('-1 month');
$output = $final_date->format('m-Y');

Try this,
$effectiveDate = date('2018-01'); <br>
echo 'Date'.$effectiveDate;<br>
$effectiveDate = date('m-y', strtotime($effectiveDate.'+-1 months'));<br>
echo 'Date'.$effectiveDate;

$currentMonth = date('m', time());
$currentDay = date('d',time());
$currentYear = date('Y',time());
$lastMonth = $currentMonth -1;
$one_month_ago=mkdate(0,0,0,$one_month_ago,$currentDay,$currentYear);
This could be rewritten more elegantly, but it works for me

I realize this is an old post, but I've been solving the same issue, and here is what I came up with to account for all the variability. This function is just trying to get relative dates, so same day of prior month, or last day of month if you are on the last day, regardless of exactly how many days a month has. So goal is given '2010-03-31' and subtract a month, we should output '2010-02-28'.
private function subtractRelativeMonth(DateTime $incomingDate): DateTime
{
$year = $incomingDate->format('Y');
$month = $incomingDate->format('m');
$day = $incomingDate->format('d');
$daysInOldMonth = cal_days_in_month(CAL_GREGORIAN, $month, $year);
if ($month == 1) { //It's January, so we have to go back to December of prior year
$month = 12;
$year--;
} else {
$month--;
}
$daysInNewMonth = cal_days_in_month(CAL_GREGORIAN, $month, $year);
if ($day > $daysInNewMonth && $month == 2) { //New month is Feb
$day = $daysInNewMonth;
}
if ($day > 29 && $daysInOldMonth > $daysInNewMonth) {
$day = $daysInNewMonth;
}
$adjustedDate = new \DateTime($year . '-' . $month . '-' . $day);
return $adjustedDate;
}

php - find date for same day of week for last year

So, in PHP i'm trying to return a date value for last year based on the same day of week.
EX: (Monday) 2011-12-19 inputted should return (Monday) 2010-12-20.
I was just doing it simply by -364 but then that was failing on leap years. I came across another function :
$newDate = $_POST['date'];
$newDate = strtotime($newDate);
$oldDate = strtotime('-1 year',$newDate);
$newDayOfWeek = date('w',$oldDate);
$oldDayOfWeek = date('w',$newDate);
$dayDiff = $oldDayOfWeek-$newDayOfWeek;
$oldDate = strtotime("$dayDiff days",$oldDate);
echo 'LAST YEAR DAY OF WEEK DATE = ' . date('Ymd', $oldDate);
however, that is failing when you try to input a Sunday date, as it does a 0 (sunday) minus 6 (saturday of last year date), and returns with a value T-6. IE inputting 2011-12-25 gets you 2010-12-19 instead of 2011-12-26.
I'm kind of stumped to find a good solution in php that will work for leap years and obviously all days of the week.
Any suggestions?
Thanks!

How about this, using PHP's DateTime functionality:
$date = new DateTime('2011-12-25'); // make a new DateTime instance with the starting date
$day = $date->format('l'); // get the name of the day we want
$date->sub(new DateInterval('P1Y')); // go back a year
$date->modify('next ' . $day); // from this point, go to the next $day
echo $date->format('Ymd'), "\n"; // ouput the date

$newDate = '2011-12-19';
date_default_timezone_set('UTC');
$newDate = strtotime($newDate);
$oldDate = strtotime('last year', $newDate);
$oldDate = strtotime(date('l', $newDate), $oldDate);
$dateFormat = 'Y-m-d l w W';
echo "This date: ", date($dateFormat, $newDate), "\n";
echo "Old date : ", date($dateFormat, $oldDate);
That gives:
This date: 2011-12-19 Monday 1 51
Old date : 2010-12-20 Monday 1 51

Use strtotime() to get a date, for the same week last year.
Use the format {$year}-W{$week}-{$weekday}, like this:
echo date("Y-m-d", strtotime("2010-W12-1"));
And you can do that for as long back you wan't:
<?php
for($i = 2011; $i > 2000; $i--)
echo date("Y-m-d", strtotime($i."-W12-1"));
?>

Make it easier :)
echo date('Y-m-d (l, W)').<br/>;
echo date('Y-m-d (l, W)', strtotime("-52 week"));
Edit: I forgot to write output: :)
2015-05-06 (Wednesday, 19)
2014-05-07 (Wednesday, 19)

<?php
$date = "2020-01-11";
$newdate = date("Y-m-d",strtotime ( '-1 year' , strtotime ( $date ) )) ;
echo $newdate;
?>
ref https://www.nicesnippets.com/blog/how-to-get-previous-year-from-date-in-php

Get first day of week in PHP?

Given a date MM-dd-yyyy format, can someone help me get the first day of the week?

Here is what I am using...
$day = date('w');
$week_start = date('m-d-Y', strtotime('-'.$day.' days'));
$week_end = date('m-d-Y', strtotime('+'.(6-$day).' days'));
$day contains a number from 0 to 6 representing the day of the week (Sunday = 0, Monday = 1, etc.).
$week_start contains the date for Sunday of the current week as mm-dd-yyyy.
$week_end contains the date for the Saturday of the current week as mm-dd-yyyy.

Very simple to use strtotime function:
echo date("Y-m-d", strtotime('monday this week')), "\n";
echo date("Y-m-d", strtotime('sunday this week')), "\n";
It differs a bit across PHP versions:
Output for 5.3.0 - 5.6.6, php7#20140507 - 20150301, hhvm-3.3.1 - 3.5.1
2015-03-16
2015-03-22
Output for 4.3.5 - 5.2.17
2015-03-23
2015-03-22
Output for 4.3.0 - 4.3.4
2015-03-30
2015-03-29
Comparing at Edge-Cases
Relative descriptions like this week have their own context. The following shows the output for this week monday and sunday when it's a monday or a sunday:
$date = '2015-03-16'; // monday
echo date("Y-m-d", strtotime('monday this week', strtotime($date))), "\n";
echo date("Y-m-d", strtotime('sunday this week', strtotime($date))), "\n";
$date = '2015-03-22'; // sunday
echo date("Y-m-d", strtotime('monday this week', strtotime($date))), "\n";
echo date("Y-m-d", strtotime('sunday this week', strtotime($date))), "\n";
Againt it differs a bit across PHP versions:
Output for 5.3.0 - 5.6.6, php7#20140507 - 20150301, hhvm-3.3.1 - 3.5.1
2015-03-16
2015-03-22
2015-03-23
2015-03-29
Output for 4.3.5 - 5.0.5, 5.2.0 - 5.2.17
2015-03-16
2015-03-22
2015-03-23
2015-03-22
Output for 5.1.0 - 5.1.6
2015-03-23
2015-03-22
2015-03-23
2015-03-29
Output for 4.3.0 - 4.3.4
2015-03-23
2015-03-29
2015-03-30
2015-03-29

strtotime('this week', time());
Replace time(). Next sunday/last monday methods won't work when the current day is sunday/monday.

Keep it simple :
<?php
$dateTime = new \DateTime('2020-04-01');
$monday = clone $dateTime->modify(('Sunday' == $dateTime->format('l')) ? 'Monday last week' : 'Monday this week');
$sunday = clone $dateTime->modify('Sunday this week');
?>
Source : PHP manual
NB: as some user commented the $dateTime value will be modified.

$givenday = date("w", mktime(0, 0, 0, MM, dd, yyyy));
This gives you the day of the week of the given date itself where 0 = Sunday and 6 = Saturday. From there you can simply calculate backwards to the day you want.

This question needs a good DateTime answer:-
function firstDayOfWeek($date)
{
$day = DateTime::createFromFormat('m-d-Y', $date);
$day->setISODate((int)$day->format('o'), (int)$day->format('W'), 1);
return $day->format('m-d-Y');
}
var_dump(firstDayOfWeek('06-13-2013'));
Output:-
string '06-10-2013' (length=10)
This will deal with year boundaries and leap years.

EDIT: the below link is no longer running on the version of PHP stated. It is running on PHP 5.6 which improves the reliability of strtotime, but isn't perfect! The results in the table are live results from PHP 5.6.
For what it's worth, here is a breakdown of the wonky behavior of strtotime when determining a consistent frame of reference:
http://gamereplays.org/reference/strtotime.php
Basically only these strings will reliably give you the same date, no matter what day of the week you're currently on when you call them:
strtotime("next monday");
strtotime("this sunday");
strtotime("last sunday");

Assuming Monday as the first day of the week, this works:
echo date("M-d-y", strtotime('last monday', strtotime('next week', time())));

The following code should work with any custom date, just uses the desired date format.
$custom_date = strtotime( date('d-m-Y', strtotime('31-07-2012')) );
$week_start = date('d-m-Y', strtotime('this week last monday', $custom_date));
$week_end = date('d-m-Y', strtotime('this week next sunday', $custom_date));
echo '<br>Start: '. $week_start;
echo '<br>End: '. $week_end;
I tested the code with PHP 5.2.17 Results:
Start: 30-07-2012
End: 05-08-2012

How about this?
$first_day_of_week = date('m-d-Y', strtotime('Last Monday', time()));
$last_day_of_week = date('m-d-Y', strtotime('Next Sunday', time()));

This is what I am using to get the first and last day of the week from any date.
In this case, monday is the first day of the week...
$date = date('Y-m-d') // you can put any date you want
$nbDay = date('N', strtotime($date));
$monday = new DateTime($date);
$sunday = new DateTime($date);
$monday->modify('-'.($nbDay-1).' days');
$sunday->modify('+'.(7-$nbDay).' days');

Here I am considering Sunday as first & Saturday as last day of the week.
$m = strtotime('06-08-2012');
$today = date('l', $m);
$custom_date = strtotime( date('d-m-Y', $m) );
if ($today == 'Sunday') {
$week_start = date("d-m-Y", $m);
} else {
$week_start = date('d-m-Y', strtotime('this week last sunday', $custom_date));
}
if ($today == 'Saturday') {
$week_end = date("d-m-Y", $m);
} else {
$week_end = date('d-m-Y', strtotime('this week next saturday', $custom_date));
}
echo '<br>Start: '. $week_start;
echo '<br>End: '. $week_end;
Output :
Start: 05-08-2012
End: 11-08-2012

How about this?
$day_of_week = date('N', strtotime($string_date));
$week_first_day = date('Y-m-d', strtotime($string_date . " - " . ($day_of_week - 1) . " days"));
$week_last_day = date('Y-m-d', strtotime($string_date . " + " . (7 - $day_of_week) . " days"));

Just use date($format, strtotime($date,' LAST SUNDAY + 1 DAY'));

Try this:
function week_start_date($wk_num, $yr, $first = 1, $format = 'F d, Y')
{
$wk_ts = strtotime('+' . $wk_num . ' weeks', strtotime($yr . '0101'));
$mon_ts = strtotime('-' . date('w', $wk_ts) + $first . ' days', $wk_ts);
return date($format, $mon_ts);
}
$sStartDate = week_start_date($week_number, $year);
$sEndDate = date('F d, Y', strtotime('+6 days', strtotime($sStartDate)));
(from this forum thread)

This is the shortest and most readable solution I found:
<?php
$weekstart = strtotime('monday this week');
$weekstop = strtotime('sunday this week 23:59:59');
//echo date('d.m.Y H:i:s', $weekstart) .' - '. date('d.m.Y H:i:s', $weekstop);
?>
strtotime is faster than new DateTime()->getTimestamp().

$monday = date('d-m-Y',strtotime('last monday',strtotime('next monday',strtotime($date))));
You have to get next monday first then get the 'last monday' of next monday. So if the given date is monday it will return the same date not last week monday.

$string_date = '2019-07-31';
echo $day_of_week = date('N', strtotime($string_date));
echo $week_first_day = date('Y-m-d', strtotime($string_date . " - " . ($day_of_week - 1) . " days"));
echo $week_last_day = date('Y-m-d', strtotime($string_date . " + " . (7 - $day_of_week) . " days"));

Given PHP version pre 5.3 following function gives you a first day of the week of given date (in this case - Sunday, 2013-02-03):
<?php
function startOfWeek($aDate){
$d=strtotime($aDate);
return strtotime(date('Y-m-d',$d).' - '.date("w",$d).' days');
}
echo(date('Y-m-d',startOfWeek("2013-02-07")).'
');
?>

$today_day = date('D'); //Or add your own date
$start_of_week = date('Ymd');
$end_of_week = date('Ymd');
if($today_day != "Mon")
$start_of_week = date('Ymd', strtotime("last monday"));
if($today_day != "Sun")
$end_of_week = date('Ymd', strtotime("next sunday"));

If you want Monday as the start of your week, do this:
$date = '2015-10-12';
$day = date('N', strtotime($date));
$week_start = date('Y-m-d', strtotime('-'.($day-1).' days', strtotime($date)));
$week_end = date('Y-m-d', strtotime('+'.(7-$day).' days', strtotime($date)));

A smart way of doing this is to let PHP handle timezone differences and Daylight Savings Time (DST). Let me show you how to do this.
This function will generate all days from Monday until Friday, inclusive (handy for generating work week days):
class DateTimeUtilities {
public static function getPeriodFromMondayUntilFriday($offset = 'now') {
$now = new \DateTimeImmutable($offset, new \DateTimeZone('UTC'));
$today = $now->setTime(0, 0, 1);
$daysFromMonday = $today->format('N') - 1;
$monday = $today->sub(new \DateInterval(sprintf('P%dD', $daysFromMonday)));
$saturday = $monday->add(new \DateInterval('P5D'));
return new \DatePeriod($monday, new \DateInterval('P1D'), $saturday);
}
}
foreach (DateTimeUtilities::getPeriodFromMondayUntilFriday() as $day) {
print $day->format('c');
print PHP_EOL;
}
This will return datetimes Monday-Friday for current week. To do the same for an arbitrary date, pass a date as a parameter to DateTimeUtilities ::getPeriodFromMondayUntilFriday, thus:
foreach (DateTimeUtilities::getPeriodFromMondayUntilFriday('2017-01-02T15:05:21+00:00') as $day) {
print $day->format('c');
print PHP_EOL;
}
//prints
//2017-01-02T00:00:01+00:00
//2017-01-03T00:00:01+00:00
//2017-01-04T00:00:01+00:00
//2017-01-05T00:00:01+00:00
//2017-01-06T00:00:01+00:00
Only interested in Monday, as the OP asked?
$monday = DateTimeUtilities::getPeriodFromMondayUntilFriday('2017-01-02T15:05:21+00:00')->getStartDate()->format('c');
print $monday;
// prints
//2017-01-02T00:00:01+00:00

You parse the date using strptime() and use date() on the result:
date('N', strptime('%m-%d-%g', $dateString));

<?php
/* PHP 5.3.0 */
date_default_timezone_set('America/Denver'); //Set apprpriate timezone
$start_date = strtotime('2009-12-15'); //Set start date
//Today's date if $start_date is a Sunday, otherwise date of previous Sunday
$today_or_previous_sunday = mktime(0, 0, 0, date('m', $start_date), date('d', $start_date), date('Y', $start_date)) - ((date("w", $start_date) ==0) ? 0 : (86400 * date("w", $start_date)));
//prints 12-13-2009 (month-day-year)
echo date('m-d-Y', $today_or_previous_sunday);
?>
(Note: MM, dd and yyyy in the Question are not standard php date format syntax - I can't be sure what is meant, so I set the $start_date with ISO year-month-day)

I've come against this question a few times and always surprised the date functions don't make this easier or clearer. Here's my solution for PHP5 that uses the DateTime class:
/**
* #param DateTime $date A given date
* #param int $firstDay 0-6, Sun-Sat respectively
* #return DateTime
*/
function getFirstDayOfWeek(DateTime $date, $firstDay = 0) {
$offset = 7 - $firstDay;
$ret = clone $date;
$ret->modify(-(($date->format('w') + $offset) % 7) . 'days');
return $ret;
}
Necessary to clone to avoid altering the original date.

Another way to do it....
$year = '2014';
$month = '02';
$day = '26';
$date = DateTime::createFromFormat('Y-m-d H:i:s', $year . '-' . $month . '-' . $day . '00:00:00');
$day = date('w', $date->getTimestamp());
// 0=Sunday 6=Saturday
if($day!=0){
$newdate = $date->getTimestamp() - $day * 86400; //86400 seconds in a day
// Look for DST change
if($old = date('I', $date->getTimestamp()) != $new = date('I', $newdate)){
if($old == 0){
$newdate -= 3600; //3600 seconds in an hour
} else {
$newdate += 3600;
}
}
$date->setTimestamp($newdate);
}
echo $date->format('D Y-m-d H:i:s');

The easiest way to get first day(Monday) of current week is:
strtotime("next Monday") - 604800;
where 604800 - is count of seconds in 1 week(60*60*24*7).
This code get next Monday and decrease it for 1 week. This code will work well in any day of week. Even if today is Monday.

I found this quite frustrating given that my timezone is Australian and that strtotime() hates UK dates.
If the current day is a Sunday, then strtotime("monday this week") will return the day after.
To overcome this:
Caution: This is only valid for Australian/UK dates
$startOfWeek = (date('l') == 'Monday') ? date('d/m/Y 00:00') : date('d/m/Y', strtotime("last monday 00:00"));
$endOfWeek = (date('l') == 'Sunday') ? date('d/m/Y 23:59:59') : date('d/m/Y', strtotime("sunday 23:59:59"));

Here's a one liner for the first day of last week, and the last day of last week as a DateTime object.
$firstDay = (new \DateTime())->modify(sprintf('-%d day', date('w') + 7))
->setTime(0, 0, 0);
$lastDay = (new \DateTime())->modify(sprintf('-%d day', date('w') + 1))
->setTime(23, 59, 59);

Just to note that timestamp math can also be a solution. If you have in mind that 01.jan 1970 was a Thursday, then start of a week for any given date can be calculated with:
function weekStart($dts)
{ $res = $dts - ($dts+date('Z',$dts)+259200)%604800;
return $res + 3600*(date('I',$dts)-date('I',$res));
}
It is predictable for any timestamp and php version, using date-func ('Z', 'I') only for timezone and daylight-saving offsets. And it produces same results as:
strtotime(date('Y-m-d', $dts).' - '.(date('N', $dts)-1.' days');
and with (the best and the most elegant) mentioned:
strtotime('monday this week', $dts);

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