Theremin Thursday?

[ther-uh-min] –noun; a musical instrument with electronic tone generation, the pitch and tone volume being controlled by the distance between the player's hands and two metal rods serving as antennas.
Origin: 1925–30; named after Leo Theremin (b. 1896), Russian inventor.

[thurz-dey, -dee] –noun; the fifth day of the week, following Wednesday.

Ther·e·min Thurs·day
[ther-uh-min thurz-dey] –noun; a day to celebrate the electronic instrument invented by Leo Theremin.
Related forms: #ThereminThursday -- a hashtag used to denote twitter content related to Theremin Thursday