Setting date/time on UNIX

There are rare times that I need to update the time on some UNIX servers. If the NTP service is setup and running properly, I shouldn’t have to worry about this.

I found one of my database servers was about 5 minutes behind the correct time. I wanted to correct the time manually and I’m always forgetting the format. I can find the information using ‘man date‘ at the command prompt and reviewing the examples. However, writing about it will hopefully infuse the format in my brain and provide a quick reference in the future.

The syntax goes something like this:

date mmddhhmi

where mm = month
dd = day of month
hh = hour
mi = minute

Changing the date/time requires root access. In my case, root access is attainable using sudo.

sudo date 02201015

The command above sets the date/time to February 20, 2007 10:15am. As mentioned in the man pages, the current year is the default because no year is supplied in the setting.

6 Responses to “Setting date/time on UNIX”

  1. Ewan Says:

    If ntp is installed but not configured, you can also run ntpdate -s servername which will contact the ntp server specified and set your time exactly, like ntpd itself would do

  2. Prashant Tambe Says:

    I have a general question regarding changing the date on database server.

    In order to do some testing for daylight saving time patch, some of our people decided to change the date/time on the Linux database server running a 10.2 single instance database. They kept changing dates back and forth several times. Finally, when the dust settled, ‘ls -ltr’ showed files modified on February 11, 2007 at the end - after March 11, 2007 files.

    My question is what’s the effect of this dynamic date/time change on Oracle database? What happens to those DBMS_SCHEDULER jobs? What about internal Oracle dependency on SYSDATE,SYSTIMESTAMP etc.? Is this unhealthy to a running database? If so, then what’s the proper way of changing the date/time on a server? Shutdown the database, change the date and then restart the database?

    Now what about a RAC database? Someone changes the date on one server and doesn’t on the other. Is the database going to crash?

  3. nour Says:

    hi,

    many thanks for your useful brief,

    my question

    how can i change year time from 2006 to 2007??
    is that possible or not?

    best regards
    NOUR

  4. mrothouse Says:

    Nour,
    You can specify the year using the command below. For example, March 26, 2007 10:50am would be specified as shown below. The century/year goes at the end after the date and time.

    date 032610502007

    This information can be found in the man pages as well. Hope this helps.

    Mike

  5. charles K Says:

    in IBM server risc server 6000, i set time in root user.
    the command is

    “date 02201015″

    the date set , but after restart the date is goes to 1970.

    Please say permananat command to set date in unix.

    Thank U

  6. mrothouse Says:

    Charles,
    As mentioned in a previous comment, you can specify the year using the command below. The century/year goes at the end after the date and time. For example, March 27, 2008 10:50am would be specified as shown below.

    date 032710502008

    This works on HP-UX and Solaris. I have no AIX platform to test this on, but would imagine the information I provided can also be found in the man pages. Hope this helps.

    Mike

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