Written by Oleksandr Gavenko (AKA gavenkoa), compiled at 2015-10-05 from rev 764bb173578d.

Date and time.¶

Contents

System timer and system time.¶

Windows assume that system timer display locale time.

UTC=no - system timer display locale time, UTC=yes - UTC time:

$ cat /etc/default/rcS
UTC=no
# or UTC=yes

If system dual boot with Windows you must set UTC=no.

$ date +"%Y-%m-%d %H:%M:%S"

$ sudo date --set="2009-02-22 12:12:00" +"%Y-%m-%d %H:%M:%S"

Or set utc time:

$ sudo date --utc --set="2009-02-22 12:12:00" +"%Y-%m-%d %H:%M:%S"

May be prefer use ntpdate(8) command.

System wide configuration:

$ cat /etc/timezone

$ tzselect

$ sudo tzconfig
...

Or using tzselect:

$ sudo tzselect
...

$ sudo dpkg-reconfigure tzdata

http://en.wikipedia.org/wiki/Timestamp

http://en.wikipedia.org/wiki/Unix_time

http://en.wikipedia.org/wiki/Leap_second

Current timestamp:

$ date +%s

Timestamp for specific date/time:

$ date -d '2010-12-11' +%s
$ date -d '2010-12-11 23:59:59' +%s

$ date -d '1970-01-01 + 1234567890 seconds'