diff --git a/utils/db_structure.sql b/utils/db_structure.sql
index b22a6dd..64837a6 100644
--- a/utils/db_structure.sql
+++ b/utils/db_structure.sql
@@ -29,9 +29,9 @@
   calendar_name VARCHAR(100) NOT NULL,
   INDEX(calendar_name),
   room VARCHAR(10) NOT NULL,
-  begins DATETIME NOT NULL,
+  begins INT NOT NULL, -- UNIX timestamp de l'hora d'inici
   INDEX(begins),
-  ends DATETIME NOT NULL,
+  ends INT NOT NULL, -- UNIX timestamp de l'hora de fi
   INDEX(ends)
 );