Get week number in the year from a date PHP

Question

I want to take a date and work out its week number   So far  I have the following  It is returning 24 when it should be 42    lt  php  ddate    2012-10-18    duedt   explode  -   ddate    date   mktime 0  0  0   duedt 2    duedt 1   duedt 0     week    int date  W    date   echo  Weeknummer     week    gt    Is it wrong and a coincidence that the digits are reversed  Or am I nearly there

User · Answer

To get the week number for a date in North America I do like this:

function week_number($n)
{
    $w = date('w', $n);
    return 1 + date('z', $n + (6 - $w) * 24 * 3600) / 7;
}

$n = strtotime('2022-12-27');
printf("%s: %d\n", date('D Y-m-d', $n), week_number($n));

and get:

Tue 2022-12-27: 53

User · Answer

I have tried to solve this question for years now  I thought I found a shorter solution but had to come back again to the long story  This function gives back the right ISO week notation          calcweek  2018-12-31     gt  1901    This function calculates the production weeknumber according to the start on     monday and with at least 4 days in the new year  Given that the  date has    the following format Y-m-d then the outcome is and integer         author M S B  Bachus        param date-notation PHP  Y-m-d  showing the data as yyyy-mm-dd     return integer      function calcweek  date         1  Convert input to  year   month   day    dateset        strtotime  date      year           date  Y    dateset      month          date  m    dateset      day            date  d    dateset       referenceday   getdate mktime 0 0 0   month   day   year       jan1day        getdate mktime 0 0 0 1 1  referenceday year           2  check if  year is a  leapyear   if     year 4  0  amp  amp   year 100  0      year 400  0         leapyear   true      else        leapyear   false            3  check if  year-1 is a  leapyear   if      year-1  4  0  amp  amp    year-1  100  0       year-1  400  0          leapyearprev   true      else        leapyearprev   false            4  find the dayofyearnumber for y m d    mnth   array 0  31  59  90  120  151  181  212  243  273  304  334      dayofyearnumber    day    mnth  month-1     if    leapyear  amp  amp   month  gt  2      dayofyearnumber            5  find the jan1weekday for y  monday 1  sunday 7     yy     year-1  100     c      year-1  -  yy     g     yy   intval  yy 4      jan1weekday   1     intval  c 100  4  5   g  7         6  find the weekday for y m d    h    dayofyearnumber     jan1weekday-1      weekday   1    h-1  7         7  find if y m d falls in yearnumber y-1  weeknumber 52 or 53    foundweeknum   false    if    dayofyearnumber  lt    8- jan1weekday   amp  amp   jan1weekday  gt  4          yearnumber    year - 1      if    jan1weekday   5       jan1weekday   6  amp  amp   leapyearprev             weeknumber   53        else          weeknumber   52             foundweeknum   true      else        yearnumber    year            8  find if y m d falls in yearnumber y 1  weeknumber 1   if    yearnumber     year  amp  amp    foundweeknum        if    leapyear            i   366        else          i   365            if     i -  dayofyearnumber   lt   4 -  weekday             yearnumber    year   1         weeknumber   1         foundweeknum   true                  9  find if y m d falls in yearnumber y  weeknumber 1 through 53   if    yearnumber     year  amp  amp    foundweeknum          j    dayofyearnumber    7 -  weekday      jan1weekday - 1        weeknumber   intval   j 7        if    jan1weekday  gt  4      weeknumber--              10  output iso week number  YYWW    return   yearnumber-2000  100  weeknumber      I found out that my short solution missed the 2018-12-31 as it gave back 1801 instead of 1901  So I had to put in this long version which is correct

User · Answer

Today  using PHP s DateTime objects is better    lt  php  ddate    2012-10-18    date   new DateTime  ddate    week    date- gt format  W    echo  Weeknummer   week       It s because in mktime    it goes like this   mktime hour  minute  second  month  day  year     Hence  your order is wrong    lt  php  ddate    2012-10-18    duedt   explode  -    ddate    date    mktime 0  0  0   duedt 1    duedt 2    duedt 0     week     int date  W    date   echo  Weeknummer       week    gt

User · Answer

This get today date then tell the week number for the week    lt  php   date date  W     echo  date   Week Number      gt

User · Answer

Your code will work but you need to flip the 4th and the 5th argument   I would do it this way   date string    2012-10-18    date int   strtotime  date string    date date   date  date int    week number   date  W    date date   echo  Weeknumber    week number       Also  your variable names will be confusing to you after a week of not looking at that code  you should consider reading http   net tutsplus com tutorials php why-youre-a-bad-php-programmer

User · Answer

try this solution  date   W   strtotime   2017-01-01   1 day

User · Answer

lt  php  ddate    2012-10-18    duedt   explode  -   ddate    date   mktime 0  0  0   duedt 1    duedt 2   duedt 0     week    int date  W    date   echo  Weeknummer     week    gt    You had the params to mktime wrong - needs to be Month Day Year  not Day Month Year

User · Answer

for get week number in jalai calendar you can use this    weeknumber   date  W      number week in year  dayweek   date  w      number day in week if   dayweek     6          weeknumberint    int  weeknumber       date2int          weeknumber    string  date2int     echo  date2    result   15   week number change in saturday

User · Answer

Becomes more difficult when you need year and week  Try to find out which week is 01 01 2017   It is the 52nd week of 2016  which is from Mon 26 12 2016 - Sun 01 01 2017   After a longer search I found strftime   G- V  strtotime  quot 2017-01-01 quot     Result  2016-52  https   www php net manual de function strftime php ISO-8601 1988 week number of the given year  starting with the first week of the year with at least 4 weekdays  with Monday being the start of the week   01 through 53   The equivalent in mysql is DATE FORMAT date    x- v   https   www w3schools com sql func mysql date format asp Week where Monday is the first day of the week  01 to 53    Could not find a corresponding solution with date   or DateTime  At least not without solutions like  quot  1day  last monday quot

User · Answer

Use PHP s date function http   php net manual en function date php  date  W    yourdate

User · Answer

How about using the IntlGregorianCalendar class  Requirements  Before you start to use IntlGregorianCalendar make sure that libicu or pecl intl is installed on the Server  So run on the CLI  php -m  If you see intl in the  PHP Modules  list  then you can use IntlGregorianCalendar  DateTime vs IntlGregorianCalendar  IntlGregorianCalendar is not better then DateTime  But the good thing about IntlGregorianCalendar is that it will give you the week number as an int  Example   dateTime   new DateTime  21-09-2020 09 00 00    echo  dateTime- gt format  quot W quot       string  39    intlCalendar   IntlCalendar  fromDateTime   21-09-2020 09 00 00    echo  intlCalendar- gt get IntlCalendar  FIELD WEEK OF YEAR      integer 39

User · Answer

To get Correct Week Count for Date 2018-12-31 Please use below Code    day count   date  N  strtotime  2018-12-31      week count   date  W  strtotime  2018-12-31           if  week count   01   amp  amp  date  m  strtotime  2018-12-31     12        yr count   date  y  strtotime  2018-12-31      1   else       yr count   date  y  strtotime  2018-12-31

User · Answer

The most of the above given examples create a problem when a year has 53 weeks  like 2020   So every fourth year you will experience a week difference  This code does not    thisYear    2020    thisDate    2020-04-24     or any other custom date  weeknr   date  W   strtotime  thisDate      when you want the weeknumber of a specific week  or just enter the weeknumber yourself   tempDatum   new DateTime     tempDatum- gt setISODate  thisYear   weeknr    tempDatum start    tempDatum- gt format  Y-m-d     tempDatum- gt setISODate  thisYear   weeknr  7    tempDatum end    tempDatum- gt format  Y-m-d     echo  tempDatum start   will output the date of monday echo  tempDatum end    will output the date of sunday

User · Answer

date string    2012-10-18   echo  Weeknummer      date  W   strtotime  date string

User · Answer

The rule is that the first week of a year is the week that contains the first Thursday of the year   I personally use Zend Date for this kind of calculation and to get the week for today is this simple  They have a lot of other useful functions if you work with dates    now   Zend Date  now     week    now- gt get Zend Date  WEEK      10

User · Answer

Just as a suggestion    lt  php echo date  W   strtotime  2012-10-18       gt    Might be a little simpler than all that lot   Other things you could do     lt  php echo date  Weeknumber  W   strtotime  2012-10-18 01 00 00       gt   lt  php echo date  Weeknumber  W   strtotime  MY DATE      gt

User · Answer

function last monday  date         if   is numeric  date            date   strtotime  date       if  date  w    date     1          return  date      else         return date  Y-m-d  strtotime  last monday   date       date    2021-01-04      Enter custom date  year   date  Y  strtotime  date     date1   new DateTime  date    ldate   last monday  year  -01-01     date2   new DateTime  ldate    diff    date2- gt diff  date1 - gt format   a     diff    diff 7   week   intval  diff    1  echo  week    Returns 2

[php] Get week number (in the year) from a date PHP

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