Read Thread: Possible bug.
It depends on what you're cutting and pasting. If you cut and paste the actual clue as it's displayed to people, the formatting you use isn't going to get saved. Doesn't matter where you cut and paste from--the formatting doesn't get saved to AQ--just the text.
If you go to the "edit clue" page and cut and paste that--the formatting is part of the text you cut (either wiki or HTML markup), and if you paste that, it'll save the formatting. Well, it's not really "saving" the formatting--it's saving the text which happens to include the necessary text about how to format the text it surrounds.
You probably copied the text without the formatting information.
But as another person already mentioned, it would have just been easier to edit the plant date! Guess it's too late for that now.... Sorry about that!
Good to know---thanks and Merry Christmas.