diff --git a/drivers/i2c/chips/m41t00.c b/drivers/i2c/chips/m41t00.c
index 27fc9ff..99ab4ec 100644
--- a/drivers/i2c/chips/m41t00.c
+++ b/drivers/i2c/chips/m41t00.c
@@ -131,13 +131,13 @@ m41t00_set(void *arg)
 	if ((i2c_smbus_write_byte_data(save_client, 0, tm.tm_sec & 0x7f) < 0)
 		|| (i2c_smbus_write_byte_data(save_client, 1, tm.tm_min & 0x7f)
 			< 0)
-		|| (i2c_smbus_write_byte_data(save_client, 2, tm.tm_hour & 0x7f)
+		|| (i2c_smbus_write_byte_data(save_client, 2, tm.tm_hour & 0x3f)
 			< 0)
-		|| (i2c_smbus_write_byte_data(save_client, 4, tm.tm_mday & 0x7f)
+		|| (i2c_smbus_write_byte_data(save_client, 4, tm.tm_mday & 0x3f)
 			< 0)
-		|| (i2c_smbus_write_byte_data(save_client, 5, tm.tm_mon & 0x7f)
+		|| (i2c_smbus_write_byte_data(save_client, 5, tm.tm_mon & 0x1f)
 			< 0)
-		|| (i2c_smbus_write_byte_data(save_client, 6, tm.tm_year & 0x7f)
+		|| (i2c_smbus_write_byte_data(save_client, 6, tm.tm_year & 0xff)
 			< 0))
 
 		dev_warn(&save_client->dev,"m41t00: can't write to rtc chip\n");