a great/memorable/happy/momentous occasion

Turn every meal into a special occasion.

They marked the occasion with an open-air concert.

Their wedding turned out to be quite an occasion.

We expect you to dress for the occasion.

He was presented with the watch on the occasion of his retirement.

Every good wish to them on the occasion of their 40th anniversary.

It should have been an occasion for rejoicing, but she could not feel any real joy.

These workshops provide an occasion for talking about art.

This is not a time for specifics, but an occasion for vision.

Festivals were occasions for great celebration.

I’ll speak to him about it if the occasion arises.

I've had no occasion to visit him recently.

She doesn’t have much occasion to speak French in her new job.

Her death was the occasion of mass riots.

Art here is an occasion for education and entertainment.

I'm willing to go to court over this if the occasion arises.

LEARNit Dictionary