1 -*- mode: outline; coding: utf-8; -*-

     2 

     3 * System timer and system time.

     4 

     5 ** Windows.

     6 

     7 Windows assume that system timer display locale time.

     8 

     9 ** Debian.

    10 

    11 UTC=no - system timer display locale time, UTC=yes - UTC time.

    12 

    13   $ cat /etc/default/rcS

    14   UTC=no

    15 or

    16   UTC=yes

    17 

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

    19 

    20 * Getting current date/time.

    21 

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

    23 

    24 * Setting current date/time.

    25 

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

    27 

    28 Or set utc time:

    29 

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

    31 

    32 May be prefer use ntpdate(8) command.

    33 

    34 * Get timezone.

    35 

    36 System wide configuration:

    37 

    38   $ cat /etc/timezone

    39 

    40 * Get list of supported timezone.

    41 

    42   $ tzselect

    43 

    44 * Set timezone.

    45 

    46   $ sudo tzconfig

    47 ...

    48 

    49 Or using tzselect:

    50 

    51   $ sudo tzselect

    52 ...

    53 

    54 ** Debian Lenny.

    55 

    56   $ sudo dpkg-reconfigure tzdata

    57 

    58 * About timestamp.

    59 

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

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

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

    63 

    64 ** Get timestamp.

    65 

    66 Current timestamp:

    67 

    68   $ date +%s

    69 

    70 Timestamp for specific date/time:

    71 

    72   $ date -d '2010-12-11' +%s

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

    74 

    75 ** Convert unix timestamp to date.

    76 

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

    78