The Time Machine — Pauline David-Sax

When apologizing to her best friend proves too difficult, Bailey feels her only hope lies in building a time machine to return to the day she said something mean.  Bailey's building a time machine... not to visit ancient Egypt or King Arthur's court, but to take her to last Thursday. That’s the day she said the Thing that made her best friend so mad. But when it's complete, Bailey discovers the only thing harder than building a time machine is having the courage to revisit a moment you regret.