diff --git a/sbin/camcontrol/camcontrol.8 b/sbin/camcontrol/camcontrol.8
index 0ded75580778..ff4c6baa3fe9 100644
--- a/sbin/camcontrol/camcontrol.8
+++ b/sbin/camcontrol/camcontrol.8
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 17, 2017
+.Dd May 1, 2017
 .Dt CAMCONTROL 8
 .Os
 .Sh NAME
@@ -2488,7 +2488,7 @@ Specify the strptime format string, as documented in strptime(3).
 The time must also be specified with the
 .Fl T 
 option.
-.It Fl T
+.It Fl T Ar time
 Provide the time in the format specified with the
 .Fl f
 option.
@@ -2814,8 +2814,8 @@ drive
 .Pa ada0 .
 .Pp
 .Bd -literal -offset indent
-camcontrol timestamp sa0 -s -f "%A %c" \e
-	-T "Wednesday Wed Oct 26 21:43:57 2016"
+camcontrol timestamp sa0 -s -f "%a, %d %b %Y %T %z" \e
+	-T "Wed, 26 Oct 2016 21:43:57 -0600"
 .Ed
 .Pp
 Set the timestamp of drive
diff --git a/sbin/camcontrol/timestamp.c b/sbin/camcontrol/timestamp.c
index 771c8f7d0131..3b02937449c6 100644
--- a/sbin/camcontrol/timestamp.c
+++ b/sbin/camcontrol/timestamp.c
@@ -282,12 +282,18 @@ set_timestamp(struct cam_device *device, char *format_string,
 		ts = (uint64_t) time_value;
 	} else {
 		bzero(&time_struct, sizeof(struct tm));
-		strptime(timestamp_string, format_string, &time_struct);
+		if (strptime(timestamp_string, format_string,
+		    &time_struct) == NULL) {
+			warnx("%s: strptime(3) failed", __func__);
+			error = 1;
+			goto bailout;
+		}
 		time_value = mktime(&time_struct);
 		ts = (uint64_t) time_value;
 	}
 	/* Convert time from seconds to milliseconds */
 	ts *= 1000;
+	bzero(&ts_p, sizeof(ts_p));
 	scsi_create_timestamp(ts_p.timestamp, ts);
 
 	scsi_set_timestamp(&ccb->csio,