diff --git a/tag_database b/tag_database
index 0048c4069..6af683d23 100644
--- a/tag_database
+++ b/tag_database
@@ -342,7 +342,7 @@ without:array,beginner
 words:string,regexp,intermediate
 xProd:array,math,intermediate
 yesNo:utility,regexp,intermediate
-yesterday:uncategorized
+yesterday:date,intermediate
 zip:array,intermediate
 zipObject:array,object,intermediate
 zipWith:array,function,advanced