date.rst

Date and time.

Contents

• System timer and system time.
  • Windows.
  • Debian.
• Getting current date/time.
• Setting current date/time.
• Get timezone.
• Get list of supported timezone.
• Set timezone.
  • Debian Lenny.
• About timestamp.
  • Get timestamp.
  • Convert unix timestamp to date.

System timer and system time.

Windows.

Windows assume that system timer display locale time.

Debian.

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.

Getting current date/time.

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

Setting current date/time.

$ 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.

Get timezone.

System wide configuration:

$ cat /etc/timezone

Get list of supported timezone.

$ tzselect

Set timezone.

$ sudo tzconfig
...

Or using tzselect:

$ sudo tzselect
...

Debian Lenny.

$ sudo dpkg-reconfigure tzdata

About timestamp.

• http://en.wikipedia.org/wiki/Timestamp
• http://en.wikipedia.org/wiki/Unix_time
• http://en.wikipedia.org/wiki/Leap_second

Get timestamp.

Current timestamp:

$ date +%s

Timestamp for specific date/time:

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

Convert unix timestamp to date.

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