public static function createSemestersForGroup($group, $count, $beginYear)
{
$year = $beginYear;
$date = new DateTime();
$date->setDate($year, 1, 1);
for ($i = 1; $i <= $count; $i++) {
$GS = new GroupSemesters();
if ($i % 2) {
$date->setDate($date->format("Y"), 9, 1);
$beginDate = $date->format('U');
$date->setDate($date->format("Y") + 1, 2, 1);
$endDate = $date->format('U');
} else {
$date->setDate($date->format("Y"), 2, 10);
$beginDate = $date->format('U');
$date->setDate($date->format("Y"), 7, 1);
$endDate = $date->format('U');
}
$GS->begin_date = $beginDate;
$GS->end_date = $endDate;
$GS->group_id = $group;
$GS->semester_number = $i;
if (!GroupSemesters::find()->where(['group_id' => $group, 'semester_number' => $i])->count()) {
$GS->save();
}
}
}
