diff --git a/cache.h b/cache.h
index 49713cc5a5..8d97939c0d 100644
--- a/cache.h
+++ b/cache.h
@@ -1464,7 +1464,7 @@ struct date_mode {
 struct date_mode *date_mode_from_type(enum date_mode_type type);
 
 const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
-void show_date_relative(timestamp_t time, int tz, const struct timeval *now,
+void show_date_relative(timestamp_t time, const struct timeval *now,
 			struct strbuf *timebuf);
 int parse_date(const char *date, struct strbuf *out);
 int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
diff --git a/date.c b/date.c
index 9bc15df6f9..61449f8b2e 100644
--- a/date.c
+++ b/date.c
@@ -107,9 +107,9 @@ static int local_tzoffset(timestamp_t time)
 	return offset * eastwest;
 }
 
-void show_date_relative(timestamp_t time, int tz,
-			       const struct timeval *now,
-			       struct strbuf *timebuf)
+void show_date_relative(timestamp_t time,
+			const struct timeval *now,
+			struct strbuf *timebuf)
 {
 	timestamp_t diff;
 	if (now->tv_sec < time) {
@@ -216,7 +216,7 @@ const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
 
 		strbuf_reset(&timebuf);
 		gettimeofday(&now, NULL);
-		show_date_relative(time, tz, &now, &timebuf);
+		show_date_relative(time, &now, &timebuf);
 		return timebuf.buf;
 	}
 
diff --git a/t/helper/test-date.c b/t/helper/test-date.c
index a0837371ab..aac4d542c2 100644
--- a/t/helper/test-date.c
+++ b/t/helper/test-date.c
@@ -16,7 +16,7 @@ static void show_relative_dates(const char **argv, struct timeval *now)
 
 	for (; *argv; argv++) {
 		time_t t = atoi(*argv);
-		show_date_relative(t, 0, now, &buf);
+		show_date_relative(t, now, &buf);
 		printf("%s -> %s\n", *argv, buf.buf);
 	}
 	strbuf_release(&buf);