Question: What defines a launch as TBD? 
The next launch (Starlink 12) was initially set as `"tbd": true` but switched last night to `false`, even though the date is still not set. 

I assume that TBD is used when a launch doesn't have a date, so I format the data in my app that way, but I wanted to ask to make sure my understanding was correct (or not). Want to make sure I'm showing my users the right info.

Thanks! 