na-adjective, noun which may take the genitive case particle 'no', noun
premature; too early
Used to say that an action or decision is being taken before the appropriate time; often implies that waiting would be wiser. Common in formal or written contexts.
その計画は時期尚早だという意見が多かった。
Many were of the opinion that the plan was premature.
You should avoid making a premature judgment.
It's still too early to carry out this plan.
The committee judged that submitting the bill was premature.
There's a sense that fully adopting the new technology is still premature.
拙速 describes doing something quickly at the cost of quality, whereas 時期尚早 is about acting before the right time has come.