diff --git a/main.c b/main.c
index 82c30a6..293c41b 100644
--- a/main.c
+++ b/main.c
@@ -662,7 +662,7 @@ VNA_SHELL_FUNCTION(cmd_time)
   rtc_set_time(dt_buf[1], dt_buf[0]);
   return;
 usage:
-  shell_printf("20%02X/%02X/%02X %02X:%02X:%02X\r\n"\
+  shell_printf("20%02x/%02x/%02x %02x:%02x:%02x\r\n"\
                "usage: time {[%s] 0-99} or {b 0xYYMMDD 0xHHMMSS}\r\n", time[6], time[5], time[4], time[2], time[1], time[0], time_cmd);
 }
 #endif