Hey there,
Excellent question!
We do indeed have a countdown widget in The Events Calendar PRO that will add a timer that runs down to the start date of the event. However, we do not have a countdown widget that is specifically tied to the end date for ticket sales. That is a neat idea!
You can certainly suggest that as a feature! In fact, we have a feature request forum and I’d love to encourage you to add it in there. When you do, it would be awesome if you could provide some additional details on how it might work. For example, what happens if there are multiple tickets and ticket types, both with the same and different sale end dates? Any bit of detail you can provide to give us a leg up will help a ton. 🙂
Sorry for the bad news, but does this at least help answer your question? Please let me know.
Cheers!
Geoff