expression
on the occasion of; at the time of; when
Formal expression used as ...に際して. Marks a special or significant occasion, often in announcements, ceremonies, or formal writing.
See also: に際して
開会に際して、一言ご挨拶を申し上げます。
On the occasion of the opening, I would like to say a few words of greeting.
新製品の発売に際して、記者会見
A press conference was held on the occasion of the new product launch.