Haven't we done this already? Oh, no, that was Tell a Fairy Tale Day (26
February). This one seems to have a bit more substance:

"The modern movement seems to have started in Sweden in 1991, when this
day was chosen as 'All Storytellers Day'. Storytelling groups in some
other countries used the same date, and in the early 2000s the movement
became global..."

Since 2004 each year has had a Theme, which Crystal lists:
(I like lists)
Birds, Bridges, the Moon, the Wanderer, Dreams, Neighbours, Light and
Shadow, Water, Trees, Fortune and Fate, Monsters and Dragons, Wishes,
Strong Women, Transformation, Wise Fools, Myths and Legends, Voyages,
New Beginnings, Lost and Found, Together We Can (2023)

Today is also World Frog Day.

<https://nationaltoday.com/world-frog-day/>

For the linguistic angle, here's a colour-coded map of the etymology
of the word for frog in various European [1] languages.

<https://www.reddit.com/r/MapPorn/comments/1awm6ej/word_for_frog_in_european_languages/>

[1] Geographically European; includes non-IE languages.

--
[English doesn't] just borrow words; on occasion, English has pursued
other languages down alleyways to beat them unconscious and rifle
their pockets for new vocabulary. (James Nicoll)