"on that occasion" is a phrase that is commonly used in written English. It is used to refer to a specific time or event in the past or present. For example: "I remember that on that occasion he was wearing a suit."
Silence, one would have thought, was prudent on that occasion.
On that occasion, Syria backed down.
On that occasion, though, Glass was killed.
"First class?" "On that occasion, yes".
Untrue on that occasion, of course.
On that occasion, Sergius renamed him Clement.
On that occasion, they discussed Jamesian marginalia.
On that occasion the man survived.
On that occasion Briscoe won.
The victors on that occasion?
"Was I? On that occasion?
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK