The Immortalists by Chloe Benjamen

This book was recommended to me while waiting for a meeting to start, a coworker gave an impromptu pitch for this book, which he was reading at the time, and then several people around the table echoed his enthusiasm for the book.  So rather than my usual approach, which is to read about a book and then getting it, this was a crowd sourced option.
The core question is that if you knew the day you were going to die, how would you live your life?
The four Gold siblings sneak out one hot and sweltering summer days and saw a fortune teller.  She gave each child the date of their death.  Set aside how telling a seven year old that they will die incredibly young might adversely affect their childhood, it is a good hook.  The two younger children know that they will die young, and they make life choices that are a direct result of the fortune telling, whereas the elder two ignore it, and are incredibly unsupportive of their sibling's choices to be more selfish about their life choices.  The book moves forward focusing on the first to dies, and then the second and so on.  It is a very effective story-telling technique, and I loved this book from the very beginning, and finished it quickly because I had trouble putting it down.