Related
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
How can I calculate the day of month in PHP with giving month, year, day of week and number of week.
Like, if I have September 2013 and day of week is Friday and number of week is 2, I should get 6. (9/6/2013 is Friday on the 2nd week.)
One way to achieve this is using relative formats for strtotime().
Unfortunately, it's not as straightforward as:
strtotime('Friday of second week of September 2013');
In order for the weeks to work as you mentioned, you need to call strtotime() again with a relative timestamp.
$first_of_month_timestamp = strtotime('first day of September 2013');
$second_week_friday = strtotime('+1 week, Friday', $first_of_month_timestamp);
echo date('Y-m-d', $second_week_friday); // 2013-09-13
Note: Since the first day of the month starts on week one, I've decremented the week accordingly.
I was going to suggest to just use strtotime() in this fashion:
$ts = strtotime('2nd friday of september 2013');
echo date('Y-m-d', $ts), PHP_EOL;
// outputs: 2013-09-13
It seems that this is not how you want the calendar to behave? But it is following a (proper) standard :)
This way its a little longer and obvious but it works.
/* INPUT */
$month = "September";
$year = "2013";
$dayWeek= "Friday";
$week = 2;
$start = strtotime("{$year}/{$month}/1"); //get first day of that month
$result = false;
while(true) { //loop all days of month to find expected day
if(date("w", $start) == $week && date("l", $start) == $dayWeek) {
$result = date("d", $start);
break;
}
$start += 60 * 60 * 24;
}
var_dump($result); // string(2) "06"
I've seen some variants on this question but I believe this one hasn't been answered yet.
I need to get the starting date and ending date of a week, chosen by year and week number (not a date)
example:
input:
getStartAndEndDate($week, $year);
output:
$return[0] = $firstDay;
$return[1] = $lastDay;
The return value will be something like an array in which the first entry is the week starting date and the second being the ending date.
OPTIONAL: while we are at it, the date format needs to be Y-n-j (normal date format, no leading zeros.
I've tried editing existing functions that almost did what I wanted but I had no luck so far.
Using DateTime class:
function getStartAndEndDate($week, $year) {
$dto = new DateTime();
$dto->setISODate($year, $week);
$ret['week_start'] = $dto->format('Y-m-d');
$dto->modify('+6 days');
$ret['week_end'] = $dto->format('Y-m-d');
return $ret;
}
$week_array = getStartAndEndDate(52,2013);
print_r($week_array);
Returns:
Array
(
[week_start] => 2013-12-23
[week_end] => 2013-12-29
)
Explained:
Create a new DateTime object which defaults to now()
Call setISODate to change object to first day of $week of $year instead of now()
Format date as 'Y-m-d' and put in $ret['week_start']
Modify the object by adding 6 days, which will be the end of $week
Format date as 'Y-m-d' and put in $ret['week_end']
A shorter version (works in >= php5.3):
function getStartAndEndDate($week, $year) {
$dto = new DateTime();
$ret['week_start'] = $dto->setISODate($year, $week)->format('Y-m-d');
$ret['week_end'] = $dto->modify('+6 days')->format('Y-m-d');
return $ret;
}
Could be shortened with class member access on instantiation in >= php5.4.
Many years ago, I found this function:
function getStartAndEndDate($week, $year) {
$dto = new DateTime();
$dto->setISODate($year, $week);
$ret['week_start'] = $dto->format('Y-m-d');
$dto->modify('+6 days');
$ret['week_end'] = $dto->format('Y-m-d');
return $ret;
}
$week_array = getStartAndEndDate(52,2013);
print_r($week_array);
We can achieve this easily without the need for extra computations apart from those inherent to the DateTime class.
function getStartAndEndDate($year, $week)
{
return [
(new DateTime())->setISODate($year, $week)->format('Y-m-d'), //start date
(new DateTime())->setISODate($year, $week, 7)->format('Y-m-d') //end date
];
}
The setISODate() function takes three arguments: $year, $week, and $day respectively, where $day defaults to 1 - the first day of the week. We therefore pass 7 to get the exact date of the 7th day of the $week.
Slightly neater solution, using the "[year]W[week][day]" strtotime format:
function getStartAndEndDate($week, $year) {
// Adding leading zeros for weeks 1 - 9.
$date_string = $year . 'W' . sprintf('%02d', $week);
$return[0] = date('Y-n-j', strtotime($date_string));
$return[1] = date('Y-n-j', strtotime($date_string . '7'));
return $return;
}
shortest way to do it:
function week_date($week, $year){
$date = new DateTime();
return "first day of the week is ".$date->setISODate($year, $week, "1")->format('Y-m-d')
."and last day of the week is ".$date->setISODate($year, $week, "7")->format('Y-m-d');
}
echo week_date(12,2014);
You can get the specific day of week from date as bellow that I get the first and last day
$date = date_create();
// get the first day of the week
date_isodate_set($date, 2019, 1);
//convert date format and show
echo date_format($date, 'Y-m-d') . "\n";
// get the last date of the week
date_isodate_set($date, 2019, 1, 7);
//convert date format and show
echo date_format($date, 'Y-m-d') . "\n";
Output =>
2018-12-31
2019-01-06
The calculation of Roham Rafii is wrong. Here is a short solution:
// week number to timestamp (first day of week number)
function wn2ts($week, $year) {
return strtotime(sprintf('%dW%02d', $year, $week));
}
if you want the last day of the week number, you can add up 6 * 24 * 3600
This is an old question, but many of the answers posted above appear to be incorrect.
I came up with my own solution:
function getStartAndEndDate($week, $year){
$dates[0] = date("Y-m-d", strtotime($year.'W'.str_pad($week, 2, 0, STR_PAD_LEFT)));
$dates[1] = date("Y-m-d", strtotime($year.'W'.str_pad($week, 2, 0, STR_PAD_LEFT).' +6 days'));
return $dates;
}
First we need a day from that week so by knowing the week number and knowing that a week has seven days we are going to do so the
$pickADay = ($weekNo-1) * 7 + 3;
this way pickAday will be a day in our desired week.
Now because we know the year we can check which day is that.
things are simple if we only need dates newer than unix timestamp
We will get the unix timestamp for the first day of the year and add to that 24*3600*$pickADay and all is simple from here because we have it's timestamp we can know what day of the week it is and calculate the head and tail of that week accordingly.
If we want to find out the same thing of let's say 12th week of 1848 we must use another approach as we can not get the timestamp. Knowing that each year a day advances 1 weekday meaning (1st of november last year was on a sunday, this year is on a monday, exception for the leap years when it advances 2 days I believe, you can check that ). What I would do if the year is older than 1970 than make a difference between it and the needed year to know how many years are there, calculate the day of the week as my pickADay was part of 1970, shift it back one weekday for each. $shiftTimes = ($yearDifference + $numberOfLeapYears)%7, in the difference. shift the day backwords $shiftTimes, then you will know what day of the week was that day those years ago, then find the weekhead and weektail. Same thing can be used also for the future if it seems simpler. Try it if it works and tell me if it does not.
For documentation (since Google ranks this question first when searching for "php datetime start end this week").
If you need the startdate and enddate for the current week (using DateTime):
$dateTime = new DateTime('now');
$monday = clone $dateTime->modify(('Sunday' == $dateTime->format('l')) ? 'Monday last week' : 'Monday this week');
$sunday = clone $dateTime->modify('Sunday this week');
var_dump($monday->format('Y-m-d')); // e.g. 2018-06-25
var_dump($sunday->format('Y-m-d')); // e.g. 2018-07-01
Hope this will help.
The "first day of the week" is subjective. Some cultures use "Monday" others "Sunday", maybe others something else?
For my purposes, I want the first day of the week to be "Sunday" and the last day of the week to be "Saturday".
Also, using DateTime with no arguments will default to "now" which includes the current time. The following method will disregard the current time by specifying "today" in the DateTime constructor.
Furthermore the string "sunday this week" does not seem to be reliable. It actually will return Sunday the next week (according to my view of what a week is).
I've built a method which returns a PHP object containing two DateTime objects. One for the first day (Sunday) of the given week, the second for the last day (Saturday) of the given week.
function get_first_and_last_day_of_week( $year_number, $week_number ) {
// we need to specify 'today' otherwise datetime constructor uses 'now' which includes current time
$today = new DateTime( 'today' );
return (object) [
'first_day' => clone $today->setISODate( $year_number, $week_number, 0 ),
'last_day' => clone $today->setISODate( $year_number, $week_number, 6 )
];
}
Have you tried PHP relative dates? It might work.
Even if you dont want to use a specific date you cannot escape it. You can calculate a week based on the date ONLY.
Steps:
get the first day of the year
decide when the first week starts ( there are some rules that include first Thursday if I remember.
add some number of weeks (your first param). Zend_Date has an add() function where you can add weeks for example. This will give you the first day of the week.
offset and get the last day.
I would recommend working with a consistent dates sistem like Zend_Date or Pear Date.
function getStartAndEndDate($week, $year)
{
$week_start = new DateTime();
$week_start->setISODate($year,$week);
$return[0] = $week_start->format('d-M-Y');
$time = strtotime($return[0], time());
$time += 6*24*3600;
$return[1] = date('d-M-Y', $time);
return $return;
}
$dateParam = '2018-06-10';
$week = date('w', strtotime($dateParam));
$date = new DateTime($dateParam);
$firstWeek = $date->modify("-".$week." day")->format("Y-m-d H:i:s");
$endWeek = $date->modify("+6 day")->format("Y-m-d H:i:s");
echo $firstWeek."<br/>";
echo $endWeek;
will print
2018-06-10 00:00:00
2018-06-16 00:00:00
hopefully will help
Let's say I have a date in the following format: 2010-12-11 (year-mon-day)
With PHP, I want to increment the date by one month, and I want the year to be automatically incremented, if necessary (i.e. incrementing from December 2012 to January 2013).
Regards.
$time = strtotime("2010.12.11");
$final = date("Y-m-d", strtotime("+1 month", $time));
// Finally you will have the date you're looking for.
I needed similar functionality, except for a monthly cycle (plus months, minus 1 day). After searching S.O. for a while, I was able to craft this plug-n-play solution:
function add_months($months, DateTime $dateObject)
{
$next = new DateTime($dateObject->format('Y-m-d'));
$next->modify('last day of +'.$months.' month');
if($dateObject->format('d') > $next->format('d')) {
return $dateObject->diff($next);
} else {
return new DateInterval('P'.$months.'M');
}
}
function endCycle($d1, $months)
{
$date = new DateTime($d1);
// call second function to add the months
$newDate = $date->add(add_months($months, $date));
// goes back 1 day from date, remove if you want same day of month
$newDate->sub(new DateInterval('P1D'));
//formats final date to Y-m-d form
$dateReturned = $newDate->format('Y-m-d');
return $dateReturned;
}
Example:
$startDate = '2014-06-03'; // select date in Y-m-d format
$nMonths = 1; // choose how many months you want to move ahead
$final = endCycle($startDate, $nMonths); // output: 2014-07-02
Use DateTime::add.
$start = new DateTime("2010-12-11", new DateTimeZone("UTC"));
$month_later = clone $start;
$month_later->add(new DateInterval("P1M"));
I used clone because add modifies the original object, which might not be desired.
strtotime( "+1 month", strtotime( $time ) );
this returns a timestamp that can be used with the date function
You can use DateTime::modify like this :
$date = new DateTime('2010-12-11');
$date->modify('+1 month');
See documentations :
https://php.net/manual/en/datetime.modify.php
https://php.net/manual/en/class.datetime.php
UPDATE january 2021 : correct mistakes raised by comments
This solution has some problems for months with 31 days like May etc.
Exemple : this jumps from 31st May to 1st July which is incorrect.
To correct that, you can create this custom function
function addMonths($date,$months){
$init=clone $date;
$modifier=$months.' months';
$back_modifier =-$months.' months';
$date->modify($modifier);
$back_to_init= clone $date;
$back_to_init->modify($back_modifier);
while($init->format('m')!=$back_to_init->format('m')){
$date->modify('-1 day') ;
$back_to_init= clone $date;
$back_to_init->modify($back_modifier);
}
}
Then you can use it like that :
$date = new DateTime('2010-05-31');
addMonths($date, 1);
print_r($date);
//DateTime Object ( [date] => 2010-06-30 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/Berlin )
This solution was found in PHP.net posted by jenspj : https://www.php.net/manual/fr/datetime.modify.php#107592
(date('d') > 28) ? date("mdY", strtotime("last day of next month")) : date("mdY", strtotime("+1 month"));
This will compensate for February and the other 31 day months. You could of course do a lot more checking to to get more exact for 'this day next month' relative date formats (which does not work sadly, see below), and you could just as well use DateTime.
Both DateInterval('P1M') and strtotime("+1 month") are essentially blindly adding 31 days regardless of the number of days in the following month.
2010-01-31 => March 3rd
2012-01-31 => March 2nd (leap year)
Please first you set your date format as like 12-12-2012
After use this function it's work properly;
$date = date('d-m-Y',strtotime("12-12-2012 +2 Months");
Here 12-12-2012 is your date and +2 Months is increment of the month;
You also increment of Year, Date
strtotime("12-12-2012 +1 Year");
Ans is 12-12-2013
I use this way:-
$occDate='2014-01-28';
$forOdNextMonth= date('m', strtotime("+1 month", strtotime($occDate)));
//Output:- $forOdNextMonth=02
/*****************more example****************/
$occDate='2014-12-28';
$forOdNextMonth= date('m', strtotime("+1 month", strtotime($occDate)));
//Output:- $forOdNextMonth=01
//***********************wrong way**********************************//
$forOdNextMonth= date('m', strtotime("+1 month", $occDate));
//Output:- $forOdNextMonth=02; //instead of $forOdNextMonth=01;
//******************************************************************//
Just updating the answer with simple method for find the date after no of months. As the best answer marked doesn't give the correct solution.
<?php
$date = date('2020-05-31');
$current = date("m",strtotime($date));
$next = date("m",strtotime($date."+1 month"));
if($current==$next-1){
$needed = date('Y-m-d',strtotime($date." +1 month"));
}else{
$needed = date('Y-m-d', strtotime("last day of next month",strtotime($date)));
}
echo "Date after 1 month from 2020-05-31 would be : $needed";
?>
If you want to get the date of one month from now you can do it like this
echo date('Y-m-d', strtotime('1 month'));
If you want to get the date of two months from now, you can achieve that by doing this
echo date('Y-m-d', strtotime('2 month'));
And so on, that's all.
Thanks Jason, your post was very helpful. I reformatted it and added more comments to help me understand it all. In case that helps anyone, I have posted it here:
function cycle_end_date($cycle_start_date, $months) {
$cycle_start_date_object = new DateTime($cycle_start_date);
//Find the date interval that we will need to add to the start date
$date_interval = find_date_interval($months, $cycle_start_date_object);
//Add this date interval to the current date (the DateTime class handles remaining complexity like year-ends)
$cycle_end_date_object = $cycle_start_date_object->add($date_interval);
//Subtract (sub) 1 day from date
$cycle_end_date_object->sub(new DateInterval('P1D'));
//Format final date to Y-m-d
$cycle_end_date = $cycle_end_date_object->format('Y-m-d');
return $cycle_end_date;
}
//Find the date interval we need to add to start date to get end date
function find_date_interval($n_months, DateTime $cycle_start_date_object) {
//Create new datetime object identical to inputted one
$date_of_last_day_next_month = new DateTime($cycle_start_date_object->format('Y-m-d'));
//And modify it so it is the date of the last day of the next month
$date_of_last_day_next_month->modify('last day of +'.$n_months.' month');
//If the day of inputted date (e.g. 31) is greater than last day of next month (e.g. 28)
if($cycle_start_date_object->format('d') > $date_of_last_day_next_month->format('d')) {
//Return a DateInterval object equal to the number of days difference
return $cycle_start_date_object->diff($date_of_last_day_next_month);
//Otherwise the date is easy and we can just add a month to it
} else {
//Return a DateInterval object equal to a period (P) of 1 month (M)
return new DateInterval('P'.$n_months.'M');
}
}
$cycle_start_date = '2014-01-31'; // select date in Y-m-d format
$n_months = 1; // choose how many months you want to move ahead
$cycle_end_date = cycle_end_date($cycle_start_date, $n_months); // output: 2014-07-02
function dayOfWeek($date){
return DateTime::createFromFormat('Y-m-d', $date)->format('N');
}
Usage examples:
echo dayOfWeek(2016-12-22);
// "4"
echo dayOfWeek(date('Y-m-d'));
// "4"
$date = strtotime("2017-12-11");
$newDate = date("Y-m-d", strtotime("+1 month", $date));
If you want to increment by days you can also do it
$date = strtotime("2017-12-11");
$newDate = date("Y-m-d", strtotime("+5 day", $date));
For anyone looking for an answer to any date format.
echo date_create_from_format('d/m/Y', '15/04/2017')->add(new DateInterval('P1M'))->format('d/m/Y');
Just change the date format.
//ECHO MONTHS BETWEEN TWO TIMESTAMPS
$my_earliest_timestamp = 1532095200;
$my_latest_timestamp = 1554991200;
echo '<pre>';
echo "Earliest timestamp: ". date('c',$my_earliest_timestamp) ."\r\n";
echo "Latest timestamp: " .date('c',$my_latest_timestamp) ."\r\n\r\n";
echo "Month start of earliest timestamp: ". date('c',strtotime('first day of '. date('F Y',$my_earliest_timestamp))) ."\r\n";
echo "Month start of latest timestamp: " .date('c',strtotime('first day of '. date('F Y',$my_latest_timestamp))) ."\r\n\r\n";
echo "Month end of earliest timestamp: ". date('c',strtotime('last day of '. date('F Y',$my_earliest_timestamp)) + 86399) ."\r\n";
echo "Month end of latest timestamp: " .date('c',strtotime('last day of '. date('F Y',$my_latest_timestamp)) + 86399) ."\r\n\r\n";
$sMonth = strtotime('first day of '. date('F Y',$my_earliest_timestamp));
$eMonth = strtotime('last day of '. date('F Y',$my_earliest_timestamp)) + 86399;
$xMonth = strtotime('+1 month', strtotime('first day of '. date('F Y',$my_latest_timestamp)));
while ($eMonth < $xMonth) {
echo "Things from ". date('Y-m-d',$sMonth) ." to ". date('Y-m-d',$eMonth) ."\r\n\r\n";
$sMonth = $eMonth + 1; //add 1 second to bring forward last date into first second of next month.
$eMonth = strtotime('last day of '. date('F Y',$sMonth)) + 86399;
}
I find the mtkime() function works really well for this:
$start_date="2021-10-01";
$start_date_plus_a_month=date("Y-m-d", mktime(0, 0, 0, date("m",strtotime($start_date))+1, date("d",strtotime($start_date)), date("Y",strtotime($start_date))));
result: 2021-11-01
I like to subtract 1 from the 'day' to produce '2021-10-31' which can be useful if you want to display a range across 12 months, e.g. Oct 1, 2021 to Sep 30 2022
$start_date_plus_a_year=date("Y-m-d", mktime(0, 0, 0, date("m",strtotime($start_date))+12, date("d",strtotime($start_date))-1, date("Y",strtotime($start_date))));
result: 2022-09-30
The correct answer to the exact question asked is Giuseppe Canale's answer from earlier. I'm going to answer a slightly more generic question of how to increment the date by an arbitrary number of months, however.
<?php
/**
* Will return a timestamp corresponding to first day of the month that is N months into the future.
* #param int $months_later number of months into the future: 0 for current one
* #param string $today if supplied will be used as the "now" time
* #return int
*/
function rel_month_to_time($months_later, $today=null) {
if ($months_later===0) {
return is_null($today) ? time() : strtotime($today);
}
return strtotime('first day of next month', rel_month_to_time($months_later-1, $today));
}
As is many times the case, you can use recursion for these "human problems" like calendars. The above can be used to return a timestamp corresponding to "next month" -- the way we humans think of it.
<?php echo date('Y-m-d', rel_month_to_time(1, '2023-01-30'));
// 2023-02-01
As pointed by #NetVicious i corrected the code, it should work with all dates, some example:
2013-01-30 will be 2013-02-28
2013-05-15 will be 2013-05-15
2013-05-31 will be 2013-06-30
This code uses the DateTime class to create a new date object, then it adds 1 month to the date using the modify method. Next, it gets the day of the next month using the format method. If the next month's day doesn't match the original day, it modifies the date to the last day of the previous month using the modify method.
$original_date = "2013-01-30";
$original_day = date("d", strtotime($original_date));
$date = new DateTime($original_date);
$date->modify('+1 month');
$next_month_day = $date->format('d');
if ($next_month_day != $original_day) {
$date->modify('last day of previous month');
}
$new_date = $date->format('Y-m-d');
echo $new_date;
All presented solutions are not working properly.
strtotime() and DateTime::add or DateTime::modify give sometime invalid results.
Examples:
- 31.08.2019 + 1 month gives 01.10.2019 instead 30.09.2019
- 29.02.2020 + 1 year gives 01.03.2021 instead 28.02.2021
(tested on PHP 5.5, PHP 7.3)
Below is my function based on idea posted by Angelo that solves the problem:
// $time - unix time or date in any format accepted by strtotime() e.g. 2020-02-29
// $days, $months, $years - values to add
// returns new date in format 2021-02-28
function addTime($time, $days, $months, $years)
{
// Convert unix time to date format
if (is_numeric($time))
$time = date('Y-m-d', $time);
try
{
$date_time = new DateTime($time);
}
catch (Exception $e)
{
echo $e->getMessage();
exit;
}
if ($days)
$date_time->add(new DateInterval('P'.$days.'D'));
// Preserve day number
if ($months or $years)
$old_day = $date_time->format('d');
if ($months)
$date_time->add(new DateInterval('P'.$months.'M'));
if ($years)
$date_time->add(new DateInterval('P'.$years.'Y'));
// Patch for adding months or years
if ($months or $years)
{
$new_day = $date_time->format("d");
// The day is changed - set the last day of the previous month
if ($old_day != $new_day)
$date_time->sub(new DateInterval('P'.$new_day.'D'));
}
// You can chage returned format here
return $date_time->format('Y-m-d');
}
Usage examples:
echo addTime('2020-02-29', 0, 0, 1); // add 1 year (result: 2021-02-28)
echo addTime('2019-08-31', 0, 1, 0); // add 1 month (result: 2019-09-30)
echo addTime('2019-03-15', 12, 2, 1); // add 12 days, 2 months, 1 year (result: 2019-09-30)
put a date in input box then click the button get day from date in jquery
$(document).ready( function() {
$("button").click(function(){
var day = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];
var a = new Date();
$(".result").text(day[a.getDay()]);
});
});
<?php
$selectdata ="select fromd,tod from register where username='$username'";
$q=mysqli_query($conm,$selectdata);
$row=mysqli_fetch_array($q);
$startdate=$row['fromd'];
$stdate=date('Y', strtotime($startdate));
$endate=$row['tod'];
$enddate=date('Y', strtotime($endate));
$years = range ($stdate,$enddate);
echo '<select name="years" class="form-control">';
echo '<option>SELECT</option>';
foreach($years as $year)
{ echo '<option value="'.$year.'"> '.$year.' </option>'; }
echo '</select>'; ?>
I'm trying to write a calendar function like this
function get_date($month, $year, $week, $day, $direction)
{
....
}
$week is a an integer (1, 2, 3...), $day is a day (Sun, Mon, ...) or number, whichever is easier. The direction is a little confusing, because it does a different calculation.
For an example, let's call
get_date(5, 2009, 1, 'Sun', 'forward');
It uses the default, and gets the first Sunday in May ie 2009-05-03. If we call
get_date(5, 2009, 2, 'Sun', 'backward');
, it returns the second last Sunday in May ie 2009-05-24.
The language-agnostic version:
To get the first particular day of the month, start with the first day of the month: yyyy-mm-01. Use whatever function is available to give a number corresponding to the day of the week. Subtract that number from the day you are looking for; for example, if the first day of the month is Wednesday (2) and you're looking for Friday (4), subtract 2 from 4, leaving 2. If the answer is negative, add 7. Finally add that to the first of the month; for my example, the first Friday would be the 3rd.
To get the last Friday of the month, find the first Friday of the next month and subtract 7 days.
Perhaps it can be made quicker...
This was VERY interesting to code.
Please note that $direction is 1 for forward and -1 for backward to ease things up :)
Also, $day begins with a value of 1 for Monday and ends at 7 for Sunday.
function get_date($month, $year, $week, $day, $direction) {
if($direction > 0)
$startday = 1;
else
$startday = date('t', mktime(0, 0, 0, $month, 1, $year));
$start = mktime(0, 0, 0, $month, $startday, $year);
$weekday = date('N', $start);
if($direction * $day >= $direction * $weekday)
$offset = -$direction * 7;
else
$offset = 0;
$offset += $direction * ($week * 7) + ($day - $weekday);
return mktime(0, 0, 0, $month, $startday + $offset, $year);
}
I've tested it with a few examples and seems to work always, be sure to double-check it though ;)
PHP's built-in time functions make this simple.
http://php.net/manual/en/function.strtotime.php
// Get first Friday of next month.
$timestamp = strtotime('first fri of next month');
// Get second to last Friday of the current month.
$timestamp = strtotime('last fri of this month -7 days');
// Format a timestamp as a human-meaningful string.
$formattedDate = date('F j, Y', strtotime('first wed of last month'));
Note that we always want to make sure that we've defined the correct timezone for use with strtotime so that PHP has an understanding of where to compute the timestamp for relative to what time zone the machine thinks it's in.
date_default_timezone_set('America/New_York');
$formattedDate = date('F j, Y', strtotime('first wed of last month +1 week'));
strtotime() can help you. e.g. <?php
$tsFirst = strtotime('2009-04-00 next friday');
$tsLast = strtotime('2009-05-01 last friday');
echo date(DATE_RFC850, $tsFirst), " | ", date(DATE_RFC850, $tsLast);printsFriday, 03-Apr-09 00:00:00 CEST | Friday, 24-Apr-09 00:00:00 CEST
No need for calculations or loops - this is very easy to do with strtotime():
Find the the Nth or Last occurrence of a particular day of a particular a month:
/////////////////////////////////////////////////////////////////
// Quick Code
/////////////////////////////////////////////////////////////////
// Convenience mapping.
$Names = array( 0=>"Sun", 1=>"Mon", 2=>"Tue", 3=>"Wed", 4=>"Thu", 5=>"Fri", 6=>"Sat" );
// Specify what we want
// In this example, the Second Monday of Next March
$tsInMonth = strtotime('March');
$Day = 1;
$Ord = 2;
// The actual calculations
$ThisMonthTS = strtotime( date("Y-m-01", $tsInMonth ) );
$NextMonthTS = strtotime( date("Y-m-01", strtotime("next month", $tsInMonth) ) );
$DateOfInterest = (-1 == $Ord)
? strtotime( "last ".$Names[$Day], $NextMonthTS )
: strtotime( $Names[$Day]." + ".($Ord-1)." weeks", $ThisMonthTS );
/////////////////////////////////////////////////////////////////
// Explanation
/////////////////////////////////////////////////////////////////
// Specify the month of which we are interested.
// You can use any timestamp inside that month, I'm using strtotime for convenience.
$tsInMonth = strtotime('March');
// The day of interest, ie: Friday.
// It can be 0=Sunday through 6=Saturday (Like 'w' from date()).
$Day = 5;
// The occurrence of this day in which we are interested.
// It can be 1, 2, 3, 4 for the first, second, third, and fourth occurrence of the day in question in the month in question.
// You can also use -1 to fine the LAST occurrence. That will return the fifth occurrence if there is one, else the 4th.
$Ord = 3;
////////////////////////////////////////////////////////////////
// We now have all the specific values we need.
// The example values above specify the 3rd friday of next march
////////////////////////////////////////////////////////////////
// We need the day name that corresponds with our day number to pass to strtotime().
// This isn't really necessary = we could just specify the string in the first place, but for date calcs, you are more likely to have the day number than the string itself, so this is convenient.
$Names = array( 0=>"Sun", 1=>"Mon", 2=>"Tue", 3=>"Wed", 4=>"Thu", 5=>"Fri", 6=>"Sat" );
// Calculate the timestamp at midnight of the first of the month in question.
// Remember $tsInMonth is any date in that month.
$ThisMonthTS = strtotime( date("Y-m-01", $tsInMonth ) );
// Calculate the timestamp at midnight of the first of the FOLLOWING month.
// This will be used if we specify -1 for last occurrence.
$NextMonthTS = strtotime( date("Y-m-01", strtotime("next month", $tsInMonth) ) );
// Now we just format the values a bit and pass them to strtotime().
// To find the 1,2,3,4th occurrence, we work from the first of the month forward.
// For the last (-1) occurence,work we work back from the first occurrence of the following month.
$DateOfInterest = (-1 == $Ord) ?
strtotime( "last ".$Names[$Day], $NextMonthTS ) : // The last occurrence of the day in this month. Calculated as "last dayname" from the first of next month, which will be the last one in this month.
strtotime( $Names[$Day]." + ".($Ord-1)." weeks", $ThisMonthTS ); // From the first of this month, move to "next dayname" which will be the first occurrence, and then move ahead a week for as many additional occurrences as you need.
echo date('Y-m-d',strtotime('last friday'));
You can use mktime to retrieve the unix timestamp of the first day in the month:
$firstOfMonth = mktime(0, 0, 0, $month, 1, $year);
When you have the date of the first day of a certain month it's easy to retrieve the weekday for that date using date:
$weekday = date("N", $firstOfMonth);
From there it's rather easy to just step forward to get the date you're after.
function get_date($month, $year, $week, $day) {
# $month, $year: current month to search in
# $week: 0=1st, 1=2nd, 2=3rd, 3=4th, -1=last
# $day: 0=mon, 1=tue, ..., 6=sun
$startday=1; $delta=0;
if ($week < 0) {
$startday = date('t', mktime(0, 0, 0, $month, 1, $year)); # 28..31
$delta=1;
}
$start = mktime(0, 0, 0, $month, $startday, $year);
$dstart = date('w', $start)-1; # last of the month falls on 0=mon,6=sun
$offset=$day-$dstart; if ($offset<$delta){$offset+=7;}
$newday=$startday+$offset+($week*7);
return mktime(0, 0, 0, $month, $newday, $year);
}
This works for me, and based on the language-agnostic version :-)
Only too bad, I needed to do that delta-thing (for if the last day of the month is the wanted week-day, we do not need to subtract 7)
The same can be accomplished very elegantly using the DateTime class.
$time_zone = new DateTimeZone('Europe/Ljubljana');
$first_friday_of_this_month = new DateTime('first Friday of this month', $time_zone);
$last_friday_of_this_month = new DateTime('last Friday of this month', $time_zone);
echo $first_friday_of_this_month->format('Y-m-d'); # 2015-11-06
echo $last_friday_of_this_month->format('Y-m-d'); # 2015-11-27
Just find out what the first and last day of the month in question is (i.e. May 1, 2009 is a Friday and May 31, 2009 is a Sunday) I believe most PHP functions use Monday=0, Sunday=6, thus Friday=4, so you know that Sunday (6) - Friday (4) = 2, then 31-2 = 29, meaning the last friday of this month is on the 29th. For the first Friday, if the number is negative, add 7, if the number is 0, the month starts on Friday.
This seems to work perfect everytime; it takes any date provided and returns the date of the last friday of the month, even in case of 5 friday in the month.
function get_last_friday_of_month($inDate) {
$inDate = date('Y-m-24', strtotime($inDate));
$last_friday = date('Y-m-d',strtotime($inDate.' next friday'));
$next_friday = date('Y-m-d',strtotime($inDate.' next friday'));
if(date('m', strtotime($last_friday)) === date('m', strtotime($next_friday))){
$last_friday = $next_friday;
}else{
//
}
return $last_friday;
}
Below is the quickest solution and you can use in all conditions. Also you could get an array of all day of week if you tweak it a bit.
function findDate($date, $week, $weekday){
# $date is the date we are using to get the month and year which should be a datetime object
# $week can be: 0 for first, 1 for second, 2 for third, 3 for fourth and -1 for last
# $weekday can be: 1 for Monday, 2 for Tuesday, 3 for Wednesday, 4 for Thursday, 5 for Friday, 6 for Saturday and 7 for Sunday
$start = clone $date;
$finish = clone $date;
$start->modify('first day of this month');
$finish->modify('last day of this month');
$finish->modify('+1 day');
$interval = DateInterval::createFromDateString('1 day');
$period = new DatePeriod($start, $interval, $finish);
foreach($period AS $date){
$result[$date->format('N')][] = $date;
}
if($week == -1)
return end($result[$weekday]);
else
return $result[$weekday][$week];
}
$date = DateTime::createFromFormat('d/m/Y', '25/12/2016');
# find the third Wednesday in December 2016
$result = findDate($date, 2, 3);
echo $result->format('d/m/Y');
I hope this helps.
Let me know if you need any further info. ;)