With Linux, time adjusting is generally done by using date command or NTP but since in-car device can obtain the accurate time from GPS, GPS time is often used as Abs Time. Because of its advantage where this GPS demand can be done anywhere in the world, it would continue in future. Therefore, we are going to need a structure for adjusting the Linux system time. As a weak point of GPS, when cold start, it takes a long time to obtain the accurate time