public function toQuarter($range = false)
{
$quarter = ceil($this->format('m') / 3);
if ($range === false) {
return $quarter;
}
$year = $this->format('Y');
switch ($quarter) {
case 1:
return [$year . '-01-01', $year . '-03-31'];
case 2:
return [$year . '-04-01', $year . '-06-30'];
case 3:
return [$year . '-07-01', $year . '-09-30'];
case 4:
return [$year . '-10-01', $year . '-12-31'];
}
}