Even if other possibilities existed, the LaLiga organisation agreed to change the date of the match on the end of Februaru at 18.45h at the Mestalla stadium.
Some Champions League matches will be played the same evening, therefore the game will take place so early.
Here is the official announcement:
The postponed #LaLigaSantander game between @valenciacf_en & @realmadriden will be played on Feb 22 at 18:45 CET. https://t.co/OuPNs5skm9 pic.twitter.com/hs3ejgLRuM
— LaLiga (@LaLigaEN) 6 de febrero de 2017