Complex sentence: On February 21,1997, Tom took a break from the role, returning six months later on October 2, during Tom's absence Sarah Aldrich was cast as her temporary replacement airing briefly from April 2 to July 1997.
Split into simpler sentences: On February 21,1997, Tom took a break from the role, returning six months later on October 2. During Tom's absence, Sarah Aldrich was cast as her temporary replacement airing briefly from April 2 to July 1997.