Then last month this one showed up: "bulk move meeting maker oracle calendar" (right in there with "calendar migration oracle to exchange" and "meeting maker exchange calendar convert").
Yes, Oracle does have a process to convert Meeting Maker into Oracle Calendar.
They smartly used the Meeting Maker export DAT format (just as we do - it's independent of operating system so it's the most natural format and live Meeting Maker data is a horror show of complexity).
BUT when we ran the MM to OCS conversion (a ways back when we were figuring out how to convert Oracle Calendar to Exchange), we discovered they had missed several key attributes and in general failed to impress us with their solution (we did try licensing our tech to them but they were not interested). Since their own published report example consists mainly of "Nothing to import" messages, you should be appropriately wary.
Sidebar: Turnabout fair play with an "X" to Paul Lynde. That's the same
strategy we use to move data OUT of OCS, using the utilities Oracle provides for moving calendar data between servers.
Cornell did this nice guide when they migrated out of Meeting Maker into OCS and Penn State apparently moved last year.
If you want a real geek instance of calendar comedy, check out their Troubleshooting Calendar Migration Guide for their Microsoft Exchange migration consisting largely of the equivalent of "Step 2: Discard remainder of killer whale carcass" making success seem as accessible as Larry Ellison's yacht habit.
We are surprised that anybody nowadays is considering leaving one waning calendar-only product for another waning calendar-only product.
If it works for you, that's all the matters.
As always our message is: try it out for yourself beforehand and follow Reagan's maxim of "trust but verify."
But also be prepared to migrate again in a few years.