From fbada0df5811af024b94cf040905ab8a4dbea7a7 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Tue, 4 Feb 2020 16:10:31 +0100
Subject: [PATCH] periph_common/rtc: handle m_mday == 0 in rtc_tm_normalize()

---
 drivers/periph_common/rtc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/periph_common/rtc.c b/drivers/periph_common/rtc.c
index 947cb6d312..85576b1b5f 100644
--- a/drivers/periph_common/rtc.c
+++ b/drivers/periph_common/rtc.c
@@ -138,6 +138,10 @@ void rtc_tm_normalize(struct tm *t)
 {
     div_t d;
 
+    if (t->tm_mday == 0) {
+        t->tm_mday = 1;
+    }
+
     d = div(t->tm_sec, 60);
     t->tm_min += d.quot;
     t->tm_sec  = d.rem;