Ruby Red by Kerstin Gier, the time traveling ability is passed through very specific genetics. Everyone expected Gwen's cousin to manifest the ability. Instead Gwen ends up being the very unprepared time travler.
In Hourglass by Myra McEntire, Emerson is afraid she is going crazy because she sees visions of the past. It turns out that it's because she can travel into the past. She may be able to use her ability to prevent someone's death.
In Tempest by Julie Cross, Jackson's time traveling trips never affect the present. Then he gets stuck two years in the past and becomes determined to change the tragedy that sent him there.
Have any of your books taken you to the past or the future recently?