Custom sql date table unknown dates

[wjadevries]

I have a question I can't find anywhere.
Some records do not have a shipping date yet (still unknown), so I need an unknown date (in the future, but also in the past for a validfrom).
How do I do that?
In sql, I set an unknown future date to 9999-12-31 and an unknown past date to 0000-01-01, but PowerBI requires as sql date dimension to have a continuous date range.
This would mean I have to fill the date dimension completely from 0000 til 9999, which is stupid.
Does anyone have a suggestion/solution?

[amitchandak]

@wjadevries , better to leave them blank/null

you can have measure to check blank dates

countrows(filter(Table, isblank(Table[validfrom]) ) )