also: てきき
noun
right time; appropriate time; proper time
Used for the optimal or correct timing for an action, especially in formal or technical contexts such as agriculture, business, or medicine.
稲の収穫は適期を逃さないように行う。
We harvest the rice without missing the right time.
投資の適期を見極めるのは難しい。
It is difficult to determine the right time for investment.
Compound of 適 (suitable, appropriate) and 期 (period, time). The reading てっき is a standard on'yomi combination, while てきき is a less common variant.