public function testPreviousMonth() { $objDate = new class_date(20130101120000); $objDate->setPreviousMonth(); $this->assertEquals($objDate->getLongTimestamp(), 20121201120000); $objDate = new class_date(20130430120000); $objDate->setPreviousMonth(); $this->assertEquals($objDate->getLongTimestamp(), 20130330120000); $objDate = new class_date(20130331120000); $objDate->setPreviousMonth(); $this->assertEquals($objDate->getLongTimestamp(), 20130228120000); $objDate = new class_date(20130831120000); $objDate->setPreviousMonth(); $this->assertEquals($objDate->getLongTimestamp(), 20130731120000); }