Why can't I find a Clan War?

Why can't I find a Clan War?

Clans are paired using a matchmaking algorithm. This ensures that Clans of similar strength are pitted against one another.  Because so many players and factors come into play in matchmaking, Clan War matches take longer to find than matches in multiplayer or VS Battle attacks. 

If the matchmaking system has been searching for a while, it is best to leave it running in the background. You can still enjoy Clash of Clans in the meantime. Select the "Return Home" (1) icon in the bottom left corner of the matchmaking screen to return to your village without interrupting the matchmaking process.

Note: pressing "Cancel" (2) in Clan Wars matchmaking will dismiss the search altogether. 

Once an opponent has been found, you will receive a notification on the Clan Wars icon. A 23-hour Preparation Day starts as soon as your match has been found.