What it means
折に means “on the occasion of” or “when,” presenting an event as a particular opportunity or circumstance. It is a formal expression used in writing, speeches, announcements, and ceremonious statements. It commonly follows a noun with の, a verb in the dictionary form, or a verb in the past form.
Usage note
折に is more formal and deliberate than ときに and is not usually used in casual conversation. With a noun, の before 折に is normally required.
How to use it
出張の折に、旧友を訪ねました。
On the occasion of the business trip, I visited an old friend.
京都を訪れる折に、古い寺院を記録しました。
When visiting Kyoto, I recorded an old temple.
先日お目にかかった折に、研究計画について相談しました。
When I saw you the other day, I consulted you about the research plan.
出張の折に、旧友を訪ねた。
On the occasion of the business trip, I visited an old friend.
京都を訪れる折に、古い寺院を記録した。
When visiting Kyoto, I recorded an old temple.
先日お目にかかった折に、研究計画について相談した。
When I saw you the other day, I consulted you about the research plan.