SYSDATE in PostgreSQL !?

How can I define a table with columns with sysdate as the default value..

If there is no SYSDATE defined in PostgreSQL , what can I do ?

Any help is appreciated.

CREATE TABLE channels (
channelID NUMBER PRIMARY KEY,
name VARCHAR2(64) NOT NULL,
status INTEGER NOT NULL,
remedyID VARCHAR2(15) UNIQUE,
remedySchemaID NUMBER default 48,
remedyLastModified INTEGER,
updateTimeStamp DATE default (SYSDATE),
createTimeStamp DATE default (SYSDATE)
);

Regards,
Louie Kwan