The Date Continues.
On March 19, Date A Live celebrates its 10th anniversary! It was celebrated since its first light novel publishing date which was dated on March 19, 2011. The staff tweeted about this.
なんと今日は?精霊の日?なんですね。— デート・ア・ライブ[公式] (@date_a_info) March 18, 2021
Date A Live (デート・ア・ライブ) is a Japanese light novel series written by Kōshi Tachibana and illustrated by Tsunako(つなこ). Fujimi Shobo (KADOKAWA) published 22 volumes from March 2011 to March 2020 under their Fujimi Fantasia Bunko imprint.
Several Anime adaptations and movies were made ever since year 2013, spanning for at least 3 seasons plus one upcoming season 4 on October 2021. (Wikipedia)