用PHP手动计算两个日期之间的周数

Question

I'm trying to calculate the number of months and weeks since a particular date instead of from the beginning of the year.

It shouldn't follow calendar months but should instead count a month as every 4 weeks, and begin from a specified date. I need to be able to display the number of months, and also what week it is (1, 2, 3 or 4).

I want to put in a start date, and have it then count what month and week is it from that start date e.g if the start date is set to Mon 1st August it should show Month 1, Week 1 and so on.

My code is below. I tested it with some different start dates. Here's a list of what the code below generates and what it should display

Jun-20: Should be Week 2 - Shows as Week 0

Jun-27: Should be Week 1 - Shows as Week 3

Jul-04: Should be Week 4 - Shows as Week 2

Jul-11: Should be Week 3 - Shows as Week 1

Jul-18: Should be Week 2 - Shows as Week 0

$monthNumber          = 5;
$monthStartDate       = '2016-06-13';
$currentStartWeekDate = date('l') != 'Monday' ? date("Y-m-d", strtotime("last monday")) : date("Y-m-d"); // get the current week's Monday's date

$weekDateCounter      = $monthStartDate;
$currentWeekNumber    = 0;

while ($weekDateCounter != $currentStartWeekDate){
  $currentWeekNumber += 1;
  $weekDateCounter    = date("Y-m-d", strtotime($weekDateCounter . "+7 days"));
  
  //
  if ($currentWeekNumber == 4){
    $currentWeekNumber  = 0; // reset week number
    $monthNumber       += 1; // increment month number
  }
}

I am really at a loss with this and could use any help!

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Answer 1

Your approach seems overly complicated:

function weekCounter($startDate,$endDate=null){

    //use today as endDate if no date was supplied
    $endDate = $endDate? : date('Y-m-d');

    //calculate # of full weeks between dates
    $secsPerWeek = 60 * 60 * 24 * 7;
    $fullWeeks = 
            floor((strtotime($endDate) - strtotime($startDate))/$secsPerWeek);

    $fullMonths = floor($fullWeeks/4);
    $weeksRemainder = $fullWeeks % 4; // weeks that don't fit in a month

    //increment from 0-base to 1-base, so first week is Week 1. Same with months
    $fullMonths++; $weeksRemainder++;

    //return months and weeks in an array
    return [$fullMonths,$weeksRemainder];
}

You can call the function this way, and capture months and weeks:

//list() will assign the array members from weekCounter to the vars in list
list($months,$weeks) = weekCounter('2016-06-07'); //no end date, so today is used

//now $months and $weeks can be used as you wish
echo "Month: $months, Week: $weeks"; //outputs Month: 2, Week: 2

Live demo