fix bad logic

diff --git a/the_perfect_clock.ino b/the_perfect_clock.ino
index 2ca7d1f0c5be1ede9bbf0c9c022d0747742e0e04..917f5688e69da72cf5f82c19c7e853b5a8717422 100644 (file)
--- a/the_perfect_clock.ino
+++ b/the_perfect_clock.ino
@@ -313,7 +313,7 @@ void calibrate()
   static unsigned long last_calib = -86398000;
   unsigned long m = millis();
   unsigned long mm = m - last_calib;
-  if (50000 < mm < 70000) {
+  if ((50000 < mm) && (mm < 70000)) {
     millis_per_minute = mm;
   }
   last_calib = m;