So [this project I've told you to do but not given you any details], when do you think you can get it done by?

I don't know. I don't know enough about the project, its priority as compared with my other things on my plate, to say when it can get done.

But I need a date to write in the WIP Date column.

I don't know what that date might be.

But I need a date in this column.

I could take a guess but that's all it would be so in all likelyhood, not worth a damn.

But I need a date, just give me a date the project could be done by. We can always change it later.

If you can change it later, what's the point of the date now?

I need a date for this column.

But if I just give you a date, that I will change later - that date is worthless and means nothing.

But I need a date.

Okay. August 30th.

Great. You're sure you can get the project done by that time?

No. I don't know enough about the project to know if I can get it done by then. You told me you needed a date. 

I do, I need a date for the column. Can you get the project done by August 30th?

I don't know. With more detail about the project I suggest that date will change and become more accurate.

Yes but can you get the project done by that date?