PHP week to quarter (date)

Question

i store a date information as week into my SQL database table as a varchar. Example: 2022-W10 I want to have the quarter out of this week. Which is in my example Quarter 1 Year 2022. Is there any possibility in PHP? I have not found anything on the PHP date() documentation for this.

Should the first day of the week determine the quarter? Keep in mind that some weeks might start in one quarter and end in another. — Hendrik, Mar 15 '22 at 09:18
True this can happen. I guess the first day makes sense. Thank you for this hint. — Mischa Mustermann, Mar 15 '22 at 09:19
Does this answer your question? [How to convert week number and year into unix timestamp?](https://stackoverflow.com/questions/5763340/how-to-convert-week-number-and-year-into-unix-timestamp) — Andrea Olivato, Mar 15 '22 at 09:35
Once you have the date, [deducing the quarter](https://stackoverflow.com/questions/1234443/easy-way-to-get-day-number-of-current-quarter) should be immediate — Andrea Olivato, Mar 15 '22 at 09:36

jspit · Accepted Answer · 2022-03-15T12:09:38.507

A date object can be created directly from a string such as '2022-W10' and the month can be determined using the format method. The calculation of the quarter is then just some school math.

$dateFromDb = '2022-W10';

$month = date_create($dateFromDb)->format('n');
$quarter = (int)(($month+2)/3);  //int(1)

If the year is also required, this solution is available:

$dateFromDb = '2022-W49';

$dateTime = date_create($dateFromDb);
$quarter = (int)(($dateTime->format('n')+2)/3);

echo 'Quarter '.$quarter.' Year '.$dateTime->format('Y');

score 0 · Answer 2 · answered Mar 15 '22 at 10:00

I mean this problem can be solved by next steps:

<?php
$date = '2022-W10';

// 1. parce year & week from string
preg_match('/(\d{4})-W(\d+)/', $date, $matches);
$year = $matches[1];
$week_no = $matches[2];
printf('Year: %d, Week no.: %d' . PHP_EOL, $year, $week_no);

// 2. create date by year & week number
$week_start = new DateTime();
$week_start->setISODate($year, $week_no);

// 3. get month number from date
$month = $week_start->format('n');
printf('Month: %d' . PHP_EOL, $month);

// 4. get quarter
$quarter = ceil($month/3);

printf('Quarter: %d' . PHP_EOL, $quarter);

Test PHP date conversion online

PHP week to quarter (date)

2 Answers2