quarter.php

См. документацию.

<?
 
namespace Bitrix\Main\UI\Filter;
 
use Bitrix\Main\Type\Date;
 

class Quarter
{
    const Q1 = 1;
    const Q2 = 2;
    const Q3 = 3;
    const Q4 = 4;
    const Q1_START = 1;
    const Q1_END = 3;
    const Q2_START = 4;
    const Q2_END = 6;
    const Q3_START = 7;
    const Q3_END = 9;
    const Q4_START = 10;
    const Q4_END = 12;
 

    public static function getCurrent()
    {
        $date = new Date();
        return self::get($date);
    }
 

    public static function get(Date $date)
    {
        $currentMonth = $date->format("n");
        $currentQuarter = self::Q1;
 
        if ($currentMonth >= self::Q2_START && $currentMonth <= self::Q2_END)
        {
            $currentQuarter = self::Q2;
        }
 
        if ($currentMonth >= self::Q3_START && $currentMonth <= self::Q3_END)
        {
            $currentQuarter = self::Q3;
        }
 
        if ($currentMonth >= self::Q4_START && $currentMonth <= self::Q4_END)
        {
            $currentQuarter = self::Q4;
        }
 
        return $currentQuarter;
    }
 

    public static function getStartDate($quarter, $year)
    {
        $startMonth = constant("self::Q".$quarter."_START");
        $startDate = Date::createFromTimestamp(mktime(0, 0, 0, $startMonth, 1, $year));
        $startDateString = $startDate->toString();
 
        return $startDateString;
    }
 

    public static function getEndDate($quarter, $year)
    {
        $date = Date::createFromTimestamp(\MakeTimeStamp(self::getStartDate($quarter, $year)));
        $date->add("3 months");
        return $date->toString();
    }
}