diff --git a/firmware/drivers/rtc/rtc_as3514.c b/firmware/drivers/rtc/rtc_as3514.c
index 8b234fcafe..87861b62cf 100644
--- a/firmware/drivers/rtc/rtc_as3514.c
+++ b/firmware/drivers/rtc/rtc_as3514.c
@@ -152,7 +152,7 @@ int rtc_write_datetime(unsigned char* buf)
     seconds = buf[0]
             + buf[1]*MINUTE_SECONDS
             + buf[2]*HOUR_SECONDS
-            + buf[4]*DAY_SECONDS
+            + (buf[4]-1)*DAY_SECONDS
             + month_days*DAY_SECONDS
             + year_days*DAY_SECONDS;