定期的に、と言いたいとき
on a regular basis
が使える。
regularlyでもいいだろう。
... to download operating system updates on a regular basis.
onとbasisで検索していて以下のものも見つけた (オックスフォード現代英英辞典)
on a need-to-know basis
with people being told only the things they need to know when they need to know them, and no more than that
- Information will be released strictly on a need-to-know basis
regularで思い出したのは「常連」regular customer.