public function testIsWorkingDay()
{
$free = ['2010-01-01', '2010-11-17', '2010-12-24', '2011-01-16', '2011-04-25', '2020-04-13'];
$working = ['2010-12-31', '2011-07-20', '2010-11-11', '2020-04-14'];
foreach ($free as $day) {
$this->assertFalse(Util::isWorkDay(new Time($day)));
}
foreach ($working as $day) {
$this->assertTrue(Util::isWorkDay(new Time($day)));
}
}