diff --git a/zdump.c b/zdump.c
index 16e73ae..760491e 100644
--- a/zdump.c
+++ b/zdump.c
@@ -660,6 +660,15 @@ yeartot(intmax_t y)
 	return t;
 }
 
+
+static void
+printtm(char const *name, struct tm const *tm)
+{
+  printf(" %s={%d-%.3dT%.2d:%.2d:%.2d dst=%d}",
+	 name, tm->tm_year + 1900, tm->tm_yday,
+	 tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_isdst);
+}
+
 /* Search for a discontinuity in timezone TZ with name NAME, in the
    timestamps ranging from LOT (with broken-down time LOTMP if
    nonnull) through HIT.  LOT and HIT disagree about some aspect of
@@ -696,6 +705,20 @@ hunt(timezone_t tz, char *name, time_t lot, struct tm *lotmp, time_t hit,
 		if (t == lot)
 			break;
 		tm_ok = my_localtime_rz(tz, &t, &tm) != NULL;
+
+		printf("TRACING: lotm_ok=%d tm_ok=%d only_ok=%d lot=",
+		       lotm_ok, tm_ok, only_ok);
+		printf(tformat(), lot);
+		printf(" t=");
+		printf(tformat(), t);
+		if (lotm_ok == tm_ok && !only_ok) {
+		  printtm("tm", &tm);
+		  printtm("lotm", &lotm);
+		  printf(" delta=%jd t-lot=", delta(&tm, &lotm));
+		  printf(tformat(), t - lot);
+		}
+		printf("\n");
+
 		if (lotm_ok == tm_ok
 		    && (only_ok
 			|| (lotm_ok && tm.tm_isdst == lotm.tm_isdst