This Time Tomorrow by Emma Straub

On the eve of her 40th birthday, Alice’s life isn’t terrible. She likes her job, even if it isn’t exactly the one she expected. She’s happy with her apartment, her romantic status, and she adores her lifelong best friend. But her father is ailing, and it feels to her as if something is missing. When she wakes up the next morning she finds herself back in 1996, reliving her 16th birthday. But it isn’t just her adolescent body that shocks her, it’s her dad: the vital, 40-something version of her father with whom she is reunited. Now armed with a new perspective on her own life… Read more.