The correlatives ᴹQ. immar “any day” and immaryas “on any day” appeared in Demonstrative, Relative, and Correlative Stems (DRC) from 1948 (PE23/109), a combination of ᴹQ. imma “any” and ᴹQ. -ar(yas) “day”. As originally published in PE23, the second form was given as immanyas with an n, but Christopher Gilson confirmed the actual form was immaryas in private correspondance consistent with similar words in DRC.
Neo-Quenya: Since ᴹQ. imma “any” too closely resembles the later prefix Q. im- “same”, for purposes of Neo-Quenya I would update this to ᴺQ. ainaurë “any day” using Q. aurë for “day” and the hypothetical prefix ᴺQ. ai(a)- “any”; see that entry for discussion.
An adjective for “any” appearing in Demonstrative, Relative, and Correlative Stems (DRC). On the page where this first appeared, this was revised to amma then to umma (PE23/99 note #24-25). Despite these revisions, the rest of the document used imma- throughout in forms like ᴹQ. immane “anybody” and ᴹQ. immanome “any place”. The adjective imma could also be used substantively to mean “anything” (PE23/104).