Yes, but this year it was in the draw "rules" if anybody actually bothered to read them.
Ah right, obvious then...
...As long as you'd bothered to find, download, read and digest the whole of a 98 page document in advance...
...And then realise that there is no mention in that document of which days the ties are played other than the very vague and ultimately unhelpful rule 12.01b:
On the basis of the draw, the UEFA administration decides which UEFA
Champions League matches are to be played on Tuesdays and which on
Wednesdays .
...and so return to this thread to ask the patronising smart-arse who finds it obvious where these "draw rules" are to be found.
In fact, it's so obvious that
UEFA still haven't managed to publish the dates themselves. Bit thick of them really.