hswg: log the error message on 📅 parse fail

hswg/main.go

@@ -128,6 +128,7 @@ func (e *Entry) Published() *time.Time {
 	} else if t, err := time.Parse("2006-01-02", d); err == nil {
 		return &t
 	} else {
+		log.Printf("%s: date: %s\n", e.PathSource, err)
 		return nil
 	}
 }