From 39e24d70500359a12e263363a47af4bd426bab4b Mon Sep 17 00:00:00 2001
From: Tim McNamara <code@timmcnamara.co.nz>
Date: Thu, 4 Nov 2021 21:56:42 +1300
Subject: [PATCH] Fix offset calculation (fixes #51)

---
 ch9/ch9-clock3/src/main.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ch9/ch9-clock3/src/main.rs b/ch9/ch9-clock3/src/main.rs
index a5c49632..b3c644c9 100644
--- a/ch9/ch9-clock3/src/main.rs
+++ b/ch9/ch9-clock3/src/main.rs
@@ -39,8 +39,8 @@ struct NTPResult {
 
 impl NTPResult {
   fn offset(&self) -> i64 {
-    let duration = (self.t2 - self.t1) + (self.t4 - self.t3);
-    duration.num_milliseconds() / 2
+    let delta = self.delay();
+    delta.abs() / 2
   }
 
   fn delay(&self) -> i64 {