PREHOOK: query: DESCRIBE FUNCTION date_add
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION date_add
POSTHOOK: type: DESCFUNCTION
date_add(start_date, num_days) - Returns the date that is num_days after start_date.
PREHOOK: query: DESCRIBE FUNCTION EXTENDED date_add
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION EXTENDED date_add
POSTHOOK: type: DESCFUNCTION
date_add(start_date, num_days) - Returns the date that is num_days after start_date.
start_date is a string in the format 'yyyy-MM-dd HH:mm:ss' or 'yyyy-MM-dd'. num_days is a number. The time part of start_date is ignored.
Example:
   > SELECT date_add('2009-30-07', 1) FROM src LIMIT 1;
  '2009-31-07'