Unix time (also known as POSIX time or erroneously as Epoch time)
1.
tux@slitaz:~$ dmesg | grep cmos
rtc_cmos 00:07: RTC can wake from S4
rtc_cmos 00:07: rtc core: registered rtc_cmos as rtc0
rtc_cmos 00:07: setting system clock to 2015-05-14 10:38:31 UTC (1431599911)
2.
tux@slitaz:~$ date -d @1431599911
Thu May 14 18:38:31 CST 2015
3.
tux@slitaz:~$ date
Thu May 14 18:46:37 CST 2015
tux@slitaz:~$ date -u
Thu May 14 10:46:55 UTC 2015
tux@slitaz:~$ date -R
Thu, 14 May 2015 18:47:19 +0800
tux@slitaz:~$ date +%s
1431600482
tux@slitaz:~$ date -ud @1431600482
Thu May 14 10:48:02 UTC 2015
4.
tux@slitaz:~$ rdate -p time.nist.gov
Thu May 14 10:50:17 2015
tux@slitaz:~$ sudo rdate -s time.nist.gov
tux@slitaz:~$ date
Thu May 14 18:52:06 CST 2015
Ref:
Unix time
Unix time (also known as POSIX time or erroneously as Epoch time) is a system for describing instants in time, defined as the number of secondsthat have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970,[1][note 1] not counting leap seconds.[1][2][note 2]It is used widely in Unix-like and many other operating systems and file formats. Due to its handling of leap seconds, it is neither a linear representation of time nor a true representation of UTC.[note 3] Unix time may be checked on most Unix systems by typing
date +%s on the command line.| Example: 1431460917 (ISO 8601:2015-05-12T20:01:57Z) the Unix time when this page was last generated |
Combined date and time representations
| <date>T<time> |
A single point in time can be represented by concatenating a complete date expression, the letter T as a delimiter, and a valid time expression. For example "2007-04-05T14:30".
