mysql a statement that retrieves information published that day

SELECT * FROM `p8_memberdata` where regdate BETWEEN (UNIX_TIMESTAMP(NOW())-86440) AND NOW() 

SELECT * FROM `p8_memberdata` WHERE DATE_FORMAT(FROM_UNIXTIME(regdate),'%Y-%m-%d')= DATE_FORMAT(NOW(),'%Y-%m-%d') order by uid desc 

Article 1 preferably shows the past 24 hours, past 1 week, etc

Article 2 obtain information of the day