Auspicious Event
Joyous Occasion
noun
If you can congratulate someone for an occurrence in their life, it must be an auspicious event. You'll remember this happy event for a long, long time.
慶事 is a very formal word used to refer to an auspicious event, such as a wedding, the birth of a child, or other significant celebrations. You might encounter 慶事 in official announcements or formal congratulatory messages.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
親しい友人の慶事は自分のことの様にうれしい。
The happy events my close friends have make me as happy as if they were my own.