WHOLE CHARACTER
期qī, jī
a fixed period of time; term (定期, 学期); issue; installment (第五期); to hope for; to expect (期待)
期 is a set stretch of time — a school term, an issue of a magazine, or something you look forward to.
ZDIC: 形声; 其 (left) is the sound side, 月 (right) the meaning side.
SOUND
其qí
his; its; that (literary)
Standalone use is grammatical and literary; kept separate from its sound role in 期.
In 期: sound Shown with its documented or clearly limited role.
MEANING
月yuè
moon; month
月 can be the moon/month source or a flesh-related form in other characters; the distinction is stated where relevant.
In 期: meaning Shown with its documented or clearly limited role.