Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!

Qenya 

umanar(yas)

adverb. someday; in a certain day

The correlatives ᴹQ. umanar “someday” and um(an)aryas “in a certain day” appeared in Demonstrative, Relative, and Correlative Stems (DRC) from 1948 (PE23/109), a combination of ᴹQ. uma- “some” and ᴹQ. -ar(yas) “day”.

Neo-Quenya: For purposes of Neo-Quenya I would update this to ᴺQ. umaurë “someday” using Q. aurë “day”.

Qenya [PE23/109; PE23/110] Group: Eldamo. Published by