Looking on the internet deeply has found these results:

IN THE GRAND OCCASION. is the most popular phrase on the web.

AT THE GRAND EVENING. 111,900 results on the web	IN THE GRAND OCCASION. 149,200 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Today's meeting is a grand occasion. day politics. It's a grand occasion... for them. As MEPs, we have been confronted on several occasions recently with the problem of how to reconcile, in the minds of our voters, the grand declarations issued at summit meetings of the Heads of Government with the reality of day We heard you're celebrating a grand occasion today. to Notional reserve for officials seconded in the interests of the service not included in the grand total. Notional reserve for officials seconded in the interests of the service not included in the grand total.

AT THE GRAND EVENING.

111,900 results on the web

IN THE GRAND OCCASION.

149,200 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

Today's meeting is a grand occasion.
day politics.
It's a grand occasion... for them.
As MEPs, we have been confronted on several occasions recently with the problem of how to reconcile, in the minds of our voters, the grand declarations issued at summit meetings of the Heads of Government with the reality of day
We heard you're celebrating a grand occasion today.
to
Notional reserve for officials seconded in the interests of the service not included in the grand total.
Notional reserve for officials seconded in the interests of the service not included in the grand total.