Best Default "Value" for DateTime column

As per the design perspective,
it should always be NULL, no default value should be put in that place...

As you see if NULL is the default value, then the application can be programmed to ask the user or prompt the use to enter that date.
but if a default value is put in that place, then it may not, not only that NULL's are specifically designed for this purpose in the database.

What becomes difficult is that the table (and its data) will be used in all sorts of ways.  So I'm just looking for a general "start with this" kind of advice.  I can always modify the nature of the data later if I find it isn't working.  Understand?  So back to my original question is it better in general to leave it NULL or 1/1/1900

Hope I'm making sense.

My thoughts as well.  Just wanted to verify with someone else.

Thanks

if that answers your question, please close this by awarding the points
thanks Surendra