diff --git a/zic.c b/zic.c
index a443408..57b39d6 100644
--- a/zic.c
+++ b/zic.c
@@ -901,9 +901,10 @@ const int		signable;
 			error(errstring);
 			return 0;
 	}
-	if (hh < 0 || hh >= HOURSPERDAY ||
+	if ((hh < 0 || hh >= HOURSPERDAY ||
 		mm < 0 || mm >= MINSPERHOUR ||
-		ss < 0 || ss > SECSPERMIN) {
+		ss < 0 || ss > SECSPERMIN) &&
+		!(hh == HOURSPERDAY && mm == 0 && ss == 0)) {
 			error(errstring);
 			return 0;
 	}