I've had a disagreement with a friend over the use of 'on' concerning the the launch of a certain product. He insists it should be 'at launch' while I believe either 'on launch' or 'at launch' is fine. I would greatly appreciate any light shed on this quandary.
2 Answers
While "at launch" may be more common, I do believe it should be "on launch" simply because the launch time is just that: a time. If we were to include the place I'd be more inclined to agree with your friend (such as At [Sydney's] launching).
The game launched at Sydney on Monday.
The game launched on Monday at Sydney.
On the game's launch at Sydney.
On launch, the game blah blahed.
At the very least you could use either.
If it is being used for the launch of a product, "at launch" seems (after some very basic research...) to be more usual, with a meaning of "at [the time of] launch", as in these examples:
At launch, Sky Q will not have any 4K content available for customers
All 104 Xbox 360 Games Available At Launch Revealed
games that are broken at launch seem to be a regular occurrence
"On launch" seems to be used with a sense of "on starting", describing an action or event rather than a time:
Photoshop CC 2015 crashes on launch
Antares Rocket Explodes On Launch
Of course, this leaves a very large grey area.