diff --git a/drivers/rtc/sandbox_rtc.c b/drivers/rtc/sandbox_rtc.c
index b08d758a74..77065e49c7 100644
--- a/drivers/rtc/sandbox_rtc.c
+++ b/drivers/rtc/sandbox_rtc.c
@@ -14,55 +14,38 @@
 
 static int sandbox_rtc_get(struct udevice *dev, struct rtc_time *time)
 {
-	time->tm_sec = dm_i2c_reg_read(dev, REG_SEC);
-	if (time->tm_sec < 0)
-		return time->tm_sec;
-	time->tm_min = dm_i2c_reg_read(dev, REG_MIN);
-	if (time->tm_min < 0)
-		return time->tm_min;
-	time->tm_hour = dm_i2c_reg_read(dev, REG_HOUR);
-	if (time->tm_hour < 0)
-		return time->tm_hour;
-	time->tm_mday = dm_i2c_reg_read(dev, REG_MDAY);
-	if (time->tm_mday < 0)
-		return time->tm_mday;
-	time->tm_mon = dm_i2c_reg_read(dev, REG_MON);
-	if (time->tm_mon < 0)
-		return time->tm_mon;
-	time->tm_year = dm_i2c_reg_read(dev, REG_YEAR);
-	if (time->tm_year < 0)
-		return time->tm_year;
-	time->tm_year += 1900;
-	time->tm_wday = dm_i2c_reg_read(dev, REG_WDAY);
-	if (time->tm_wday < 0)
-		return time->tm_wday;
+	u8 buf[7];
+	int ret;
+
+	ret = dm_i2c_read(dev, REG_SEC, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	time->tm_sec  = buf[REG_SEC - REG_SEC];
+	time->tm_min  = buf[REG_MIN - REG_SEC];
+	time->tm_hour = buf[REG_HOUR - REG_SEC];
+	time->tm_mday = buf[REG_MDAY - REG_SEC];
+	time->tm_mon  = buf[REG_MON - REG_SEC];
+	time->tm_year = buf[REG_YEAR - REG_SEC] + 1900;
+	time->tm_wday = buf[REG_WDAY - REG_SEC];
 
 	return 0;
 }
 
 static int sandbox_rtc_set(struct udevice *dev, const struct rtc_time *time)
 {
+	u8 buf[7];
 	int ret;
 
-	ret = dm_i2c_reg_write(dev, REG_SEC, time->tm_sec);
-	if (ret < 0)
-		return ret;
-	ret = dm_i2c_reg_write(dev, REG_MIN, time->tm_min);
-	if (ret < 0)
-		return ret;
-	ret = dm_i2c_reg_write(dev, REG_HOUR, time->tm_hour);
-	if (ret < 0)
-		return ret;
-	ret = dm_i2c_reg_write(dev, REG_MDAY, time->tm_mday);
-	if (ret < 0)
-		return ret;
-	ret = dm_i2c_reg_write(dev, REG_MON, time->tm_mon);
-	if (ret < 0)
-		return ret;
-	ret = dm_i2c_reg_write(dev, REG_YEAR, time->tm_year - 1900);
-	if (ret < 0)
-		return ret;
-	ret = dm_i2c_reg_write(dev, REG_WDAY, time->tm_wday);
+	buf[REG_SEC - REG_SEC]  = time->tm_sec;
+	buf[REG_MIN - REG_SEC]  = time->tm_min;
+	buf[REG_HOUR - REG_SEC] = time->tm_hour;
+	buf[REG_MDAY - REG_SEC] = time->tm_mday;
+	buf[REG_MON  - REG_SEC] = time->tm_mon;
+	buf[REG_YEAR - REG_SEC] = time->tm_year - 1900;
+	buf[REG_WDAY - REG_SEC] = time->tm_wday;
+
+	ret = dm_i2c_write(dev, REG_SEC, buf, sizeof(buf));
 	if (ret < 0)
 		return ret;
 
diff --git a/test/dm/rtc.c b/test/dm/rtc.c
index 88f86581cc..e072fd618b 100644
--- a/test/dm/rtc.c
+++ b/test/dm/rtc.c
@@ -70,7 +70,20 @@ static int dm_test_rtc_set_get(struct unit_test_state *uts)
 	old_base_time = sandbox_i2c_rtc_get_set_base_time(emul, -1);
 
 	memset(&time, '\0', sizeof(time));
-	time.tm_mday = 25;
+	time.tm_mday = 3;
+	time.tm_mon = 6;
+	time.tm_year = 2004;
+	time.tm_sec = 0;
+	time.tm_min = 18;
+	time.tm_hour = 18;
+	ut_assertok(dm_rtc_set(dev, &time));
+
+	memset(&cmp, '\0', sizeof(cmp));
+	ut_assertok(dm_rtc_get(dev, &cmp));
+	ut_assertok(cmp_times(&time, &cmp, true));
+
+	memset(&time, '\0', sizeof(time));
+	time.tm_mday = 31;
 	time.tm_mon = 8;
 	time.tm_year = 2004;
 	time.tm_sec = 0;