【Android】adb shell date は System User or radio Groupじゃないと反映されない ref: http://qiita.com/operandoOS/items/61bbbed2568e27a6ee4e

file0.c

fd = open("/dev/alarm", O_RDWR);
ts.tv_sec = tv.tv_sec;
ts.tv_nsec = tv.tv_usec * 1000;
res = ioctl(fd, ANDROID_ALARM_SET_RTC, &ts);
//res = settimeofday(&tv, NULL);
if(res < 0) {
    fprintf(stderr,"settimeofday failed %s\n", strerror(errno));
    return 1;
}

file1.txt

root@vbox86p:/ # ll /dev/alarm                                                 
crw-rw-r-- system   radio     10,  54 2014-10-10 20:57 alarm