Eikas
Eikas (Greek εἰκάς from εἴκοσῐ "eíkosi", "twenty"), Eikadenfest is a holiday celebrated among Epicureans in commemoration of Epicurus and Metrodorus. It is a monthly celebration taking place on the 20th day of every month. The observance was made during Epicurus' lifetime, and provisions were made in his will to continue the practice. It became so characteristic of the Epicureans that they were given the nickname "Twentiers" ("eikadistae") by detractors. 

The day had special significance among the Greeks before Epicurus, the twentieth being sacred to the god Apollo, and also corresponding to the final day of the rites of initiation to the mysteries of Demeter. 

The observance of Eikas has recently been revived among modern Epicureans and humanists.
Q179541
Epicureans
Concept
Q43216
Epicurus
PER
Q780259
Metrodorus
PER
Q37340
Apollo
MISC
Q40730
Demeter
MISC
Q312226
humanists
Concept
Q105062720
Eikas
UNK
Q105062720
Eikas
UNK
+20^^http://www.w3.org/2001/XMLSchema#decimal
20
NUMBER
movement