Esther Earl was John Green's muse for writing The Fault In Our Stars, and her birthday falls on 8/3. The following is from her foundation's website (This Star Won't Go Out):
Before her death, author and friend John Green told Esther that he and his brother Hank wanted to celebrate her birthday as long as there were vlogbrothers videos, and that the videos on that day could be about whatever she chose. After some reflection, Esther decided she wanted it to be a day to celebrate love for family and friends. So, since 2010, August 3rd or Esther Day has become a holiday that reminds us to verbalize our love for friends and family, the important people in our lives who we might not remember to say “I love you” to very often.
Both Phoenix Books locations will be handing out paper stars to anyone who wants to celebrate. Participants can write a message of love on these stars and are encouraged to take photos with their stars and post to social media outlets with the #EstherDay marker.