时间以及时区设置
首先确认使用utc还是local time. 
UTC(Universal Time Coordinated)=GMT(Greenwich Mean Time) 
Local time 是你手表上的时间

传统的POSIX计算机(Solaris,bsd,unix)使用UTC格式 
linux可以处理UTC时间和蹩脚的Windows所使用的local time

到底是使用UTC还是local time可以这样来确定: 
如果机器上同时安装有Linux和Windows,建议使用local time 
如果机器上只安装有Linux,建议使用utc 
确定后编辑/etc/sysconfig/clock, UTC=0 是local time; UTC=1 是UTC(GMT)

1) 使用cat /etc/sysconfig/clock查看当前时区 
linux5:~ # cat /etc/sysconfig/clock
## Path:                System/Environment/Clock
## Description:         Information about your timezone and time
## Type:                string
## ServiceRestart:      boot.clock
#
# Set to "-u" if your system clock is set to UTC, and to "--localtime"
# if your clock runs that way.
#
HWCLOCK="-u"

## Type:                string(Europe/Berlin,Europe/London,Europe/Paris)
## ServiceRestart:      boot.clock
#
# Timezone (e.g. CET)
# (this will set /usr/lib/zoneinfo/localtime)
#
TIMEZONE="US/Pacific"
DEFAULT_TIMEZONE="US/Pacific"
linux5:~ #

2) 使用tzselect设置时区,最后结果如下

You can make this change permanent for yourself by appending the line
        TZ='Asia/Shanghai'; export TZ
to the file '.profile' in your home directory; then log out and log in again.

Here is that TZ value again, this time on standard output so that you
can use the /usr/bin/tzselect command in shell scripts:
Asia/Shanghai
linux5:~ #

3) 复制相应的时区文件,替换系统默认时区 
linux5:~ # cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
linux5:~ #

4) 将当前时间写入BIOS永久生效(避免重启后失效) 
linux5:~ # hwclock
Tue Jan 29 18:22:59 2008  -0.565688 seconds
linux5:~ #

10. 配置ntp客户端
编辑/etc/ntp.conf,增加一行server 10.30.1.10,其中10.30.1.105就是时钟服务器,如下
linux:/var/log # grep -v \# /etc/ntp.conf

server 10.30.1.105

查看ntp服务的状态
linux:/var/log # /etc/init.d/xntpd  status
Checking for network time protocol daemon (NTPD):                    unused

设置时区以及时间
/usr/sbin/zic -l PRC
/bin/date "+%H:%M:%S - %d-%m-%Y"

写回硬件时钟
/sbin/hwclock --hctosys --localtime
或者写回硬件时钟: hwclock --systohc

在/etc/rc.d/rc5.d创建xntp服务的启动脚本
linux:/etc/rc.d/rc5.d # ln -s ../xntpd S14xntpd
查看ntp时间调整纪录
linux:/var/log # grep ntp messages
Aug 14 07:19:51 linux ntpdate[2837]: step time server 10.30.1.105 offset 2.010174 sec
Aug 14 07:19:51 linux ntpd[2884]: ntpd 4.2.0a@1.1213-r Wed Jun 30 18:37:03 UTC 2004 (1)
Aug 14 07:19:51 linux ntpd[2884]: precision = 1.000 usec
Aug 14 07:19:51 linux ntpd[2884]: Listening on interface wildcard, 0.0.0.0#123
Aug 14 07:19:51 linux ntpd[2884]: Listening on interface wildcard, ::#123
Aug 14 07:19:51 linux ntpd[2884]: Listening on interface lo, 127.0.0.1#123
Aug 14 07:19:51 linux ntpd[2884]: Listening on interface eth0, 10.40.157.66#123
Aug 14 07:19:51 linux ntpd[2884]: kernel time sync status 0040

mmscbill:~ # date
Wed May  7 15:53:10 CST 2008
这里时区设置没有错. PRC是时区的名称,它对应/usr/share/lib/zoneinfo下的PRC时区文件.
CST是Chinese Standard Time的缩写,用在date命令的输出中.它是定义在PRC时区文件中.看
一下/usr/share/lib/zoneinfo/src下的asia文件就知道是怎么回事了.

修改系统时间(bjchenxu,laixi781211,hutuworm)
date -s “2003-04-14 cst”,cst指时区,时间设定用date -s 18:10
修改后执行clock -w 写到CMOS
hwclock --systohc
set the hardware clock to the current system time

 

zdump -v Europe/Moscow 查看时区一些设置参数