Heart of Darkness

I've read this one before – 29 years ago. But I was feeling nostalgic for some of the stories I'd read as a teen and I tracked this one down and decided to re-read it for kicks. It's a sf book in a light-hearted vein with a bumbling anti-hero named Roger Tyson who gets caught up a time warp. He meets a comely agent from the the future named Q'nell and the pair of them are pursued by the mysterious Oob the Rhox through a series of time portals. They try to figure out how to repair the damage caused by these as various people all over Earth and from different times find themselves reliving the same day over and over again. Silly, fast-moving stuff. (Written in 1970.)