For some reason I want to set the system date to earlier month in my ubuntu 12.04 machine? But I am unable to set it. When I tried to change the system time to earlier month or year getting back to the original current date. I deselected Automatically from the internet and selected Manually.

How can I do it Please guide me through. Any help will be appreciated. Thanks in advance

2 Answers 2


uninstall "ntpdate" package will disable automatic time sync. To do it, run this command in the terminal

 sudo apt-get remove ntpdate
  • If I do this, Later whenever I want to update my system time and date automatically what should I do then??
    – Chella
    Dec 20, 2012 at 9:06
  • install the package with "sudo apt-get install ntpdate" then update time with "ntpdate ntp.ubuntu.com" Check that the file /etc/cron.daily/ntpdate is executable. If not, run "sudo chmod 755 /etc/cron.daily/ntpdate"
    – Hari
    Dec 25, 2012 at 18:45

ref: For some reason I want to set the system date to earlier month but I am unable to set it

The issue:

screen shot of faulty date/time panel indicator menu item


  • today is Sun. Mar 3, 2013
  • all date changes were made "Manually" using "Time & Date Settings..." as seen in the partial window displaying 03/01/2013
  • it was possible to change the time/date indicator ap. pull down menu, circled in yellow, to a different date (eventually!!! see below) ... it was changed to Sunday, 10 March 2013
  • the top right green circled date is usually not visible and is enabled using "Time & Date Settings..." from the "Clock" tab (for clarity the calendar display was also turned off)
  • note in particular that both green and yellow circled dates in the top right corner are manifestations of the indicator-datetime menubar panel.

The simple solution is to ignore the pull down menu date and turn on the menu bar indicator panel option to display date changes instead.

The utility ntpdate is NOT the problem. The implementation of the service panel display for the time/date indicator service IS.

Note that a change of time is relatively immediate, within a minute or so, but a date change takes on another order of magnitude of time complexity to register with the time/date panel pull down menu service ie. it will happen but not for many ten's of minutes.

That the date change is effective immediately can be seen with the date terminal command, which DOES correctly show that the effective system time AND date ARE changed. This can be observed irregardless of network connectivity or any NTP daemon.

This is easily tested by simply severing ALL network connections (ie. simply dis-Enable Networking) so that any NTP service is ineffective without disturbing the install state of ntpdate.

(PS. sudo date -s 2013-04-01 is highly effective in any ambient ntpdate state.)

If the source of the problem were the ntpd or ntpdate then difficulties would manifest with both the date AND time, not just with one chronometer component.

Observe closely the discrepancy between the panel pull down menu date annotation with the panel date if displayed.

:[From Time & Date Settings and the tab Clock select both Show a clock in the menu bar and Date and month and then change the date AND compare to the pull down menu :! ;]

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