国际 NTP 快速授时服务
pool.ntp.org
0.pool.ntp.org
1.pool.ntp.org
2.pool.ntp.org
3.pool.ntp.org
asia.pool.ntp.org
谷歌
time1.google.com
time2.google.com
time3.google.com
time4.google.com
苹果
time.apple.com
time1.apple.com
time2.apple.com
time3.apple.com
time4.apple.com
time5.apple.com
time6.apple.com
time7.apple.com
微软 Windows
time.windows.com
美国标准技术研究院
time.nist.gov
time-nw.nist.gov
time-a.nist.gov
time-b.nist.gov
香港天文台
stdtime.gov.hk
