當Linux服務器的時間不對的時候，可以使用ntpdate工具來校正時間。
ntpdate簡單用法：
# ntpdate ip
# ntpdate 210.72.145.44
以下是一些可用的NTP服務器地址：
Name
IP Location 210.72.145.44 210.72.145.44 中國（國家授時中心） 133.100.11.8 133.100.11.8 日本（福岡大學） time-a.nist.gov 129.6.15.28 NIST,Gaithersburg,Maryland time-b.nist.gov 129.6.15.29 NIST,Gaithersburg,Maryland time-a.timefreq.bldrdoc.gov 132.163.4.101 NIST,Boulder,Colorado time-b.timefreq.bldrdoc.gov 132.163.4.102 NIST,Boulder,Colorado time-c.timefreq.bldrdoc.gov 132.163.4.103 NIST,Boulder,Colorado utcnist.colorado.edu 128.138.140.44 UniversityofColorado,Boulder time.nist.gov 192.43.244.18 NCAR,Boulder,Colorado time-nw.nist.gov 131.107.1.10 Microsoft,Redmond,Washington nist1.symmetricom.com 69.25.96.13 Symmetricom,SanJose,California nist1-dc.glassey.com 216.200.93.8 Abovenet,Virginia nist1-ny.glassey.com 208.184.49.9 Abovenet,NewYorkCity nist1-sj.glassey.com 207.126.98.204 Abovenet,SanJose,California nist1.aol-ca.truetime.com 207.200.81.113 TrueTime,AOLfacility,Sunnyvale,California nist1.aol-va.truetime.com 64.236.96.53 TrueTime,AOLfacility,Virginia
