have to use trait

Author: tedhorst

datetime.rs

@@ -291,6 +291,7 @@ mod tests {
 	use std::{os, fmt};
 	use extra::time::{Timespec, strptime};
 	use extra::test;
+	use super::DateTime;
 
 	fn time_str<T: super::Time>(t: T) -> ~str {
 		let tm = t.tm();