unix_timestamp()
select unix_timestamp()
unix_timestamp(string date)
select from_unixtime(unix_timestamp(),’yyyy-MM-dd HH:mm:ss’ )
to_date(string timestamp)
year(string date)
month(string date)
day(string date)
hour(string date)
minute(string date)
second(string date )
weekofyear(string date)
datediff(string enddate,string startdate)
date_add(string startdate,int days)
date_sub(string strartdate,int days)