utc_current as default value in informix

Use utc_current as default value in a field of an informix database table. My idea is to do something like this, so that when that record is inserted or updated, the value is automatically increased since datetime or timestamp doesn't work for me.

CREATE TABLE tab1
  (
    id VARCHAR(128) NOT NULL,
    update_ts  integer DEFAULT dbinfo('utc_current') ,
    modcount BIGINT,
  );