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Built-in Network Time Server

Supported Product

The built-in network time server in both Windows and OS X operating systems can synchronize your computer's clock with the University's time servers (timeserver1.upenn.edu, timeserver2.upenn.edu, timeserver3.upenn.edu) to allow you to operate in a Kerberized environment.

General Information

Availability

The Microsoft Windows built-in network time server is included with the Windows 8, Windows 7, and Windows Vista, and operating systems.

The built-in network time server is included with OS X Mountain Lion (10.8), OS X Lion (10.7), and OS X Snow Leopard (10.6).

Synchronizing your computer's clock with Penn's network time server

Kerberos requires that your Windows clock be in sync with that of the Kerberos KDC (ticket-dispensing) server. You can synchronize your computer's clock with Penn's network time server to ensure that your computer's date and time remain consistent with that of the Kerberos server.

  1. From the Start Menu, select Control Panel.

  2. From the Control Panel window, select the Date, Time, Language and Regional Options category.

  3. Click the Date and Time icon.

  4. In the Date and Time Properties window, click the Internet Time tab.

  5. Click the checkbox labeled "Automatically synchronize with and Internet time server" to activate it.

  6. Type "timeserver1.upenn.edu" in the "Server" field.

  7. Click OK button in close window and preserve settings.

  8. Close the Date and Time control panel.

Note: Penn has 3 time servers. You can use any of these servers to synchronize time. Below is a list of the Penn time servers:

  • timeserver1.upenn.edu

  • timeserver2.upenn.edu

  • timeserver3.upenn.edu

Setting the local time zone for your computer

Once you have synchronized your computer's clock, if it still differs widely from your local time, check to determine whether you have set the time zone correctly.

  1. From the Start Menu, select Control Panel.

  2. From the Control Panel window, select the Date, Time, Language and Regional Options category.

  3. Click the Date and Time icon.

  4. In the Date and Time Properties window, click the Time Zone tab.

  5. Use the pull-down menu to select the correct local time zone. For example, select the option that includes "Eastern Time (US & Canada)" for Philadelphia.

  6. Click the checkbox labeled "Automatically adjust clock for dayight savings changes" to activate it.

  7. Close Date and Time control panel.

Changing the local time zone

If you have transported your computer to another time zone and want to display the new local time, you must change the time zone designation, not the time display itself, in order to maintain proper synchronization with the network time server. For example, if you carry a laptop computer with you outside the eastern United States, or if you take your workstation outside the Eastern time zone during summer break, you should follow these instructions to reset your computer's clock.

Note: Do not attempt to manually adjust either the Current Date or Current Time fields. They will be automatically and correctly reset by steps below.

  1. From the Start Menu, select Control Panel.

  2. From the Control Panel window, select the Date, Time, Language and Regional Options category.

  3. Click the Date and Time icon.

  4. In the Date and Time Properties window, click the Time Zone tab.

  5. Use the pull-down menu to select the correct local time zone for your new location. For example, select the option that includes "United Kingdom" for Manchester, England.

  6. Click the checkbox labeled "Automatically adjust clock for dayight savings changes" to activate it.

  7. Close Date & Time control panel.

Synchronizing your computer's clock with Penn's network time server

Kerberos requires that your Macintosh clock be in sync with that of the Kerberos KDC (ticket-dispensing) server. You can synchronize your computer's clock with Penn's network time server to ensure that your computer's date and time remain consistent with that of the Kerberos server.

  1. From the Apple Menu, open the System Preferences window.

  2. Click the Date & Time icon in the System section of the window.

  3. In the Date & Time window, click the Network Time tab.

  4. Click to activate the Use a network time server checkbox, if not already checked.

  5. In the "NTP Server" field, type "timeserver1.upenn.edu", then click the Set Time Now button.
    After you click the button, a status message will appear:

    • "Synchronization Succeeded"

    • "Synchronization Failed. Your NTP Server may not be responding."
      If you receive this message, you may wish to check your spelling in the "NTP Server" field, or select a different Penn network time server. After adjusting your server settings, click the "Set Time Now" button again.

  6. Optional: To freeze your settings, click the lock icon in the lower left corner, captioned as "Click the lock to prevent further changes."
  7. Close the Date & Time window.
    Note: Penn has 3 time servers. You can use any of these servers to synchronize time. Below is a list of the Penn time servers:
  • timeserver1.upenn.edu
  • timeserver2.upenn.edu
  • timeserver3.upenn.edu

Setting the local time zone for your computer

Once you have synchronized your computer's clock, if it still differs widely from your local time, check to determine whether you have set the time zone correctly.

  1. From the Apple Menu, open the System Preferences window.

  2. Click the Date & Time icon in the System section of the window.

  3. In the Date & Time window, click the Time Zone tab.

  4. As noted above the world map, "Click your part of the world and then choose a time zone from the pop-up menu."
    For example, users in Philadelphia would click the eastern region of the United States, then select "U.S.A.-Eastern" from the resulting pop-up menu.

  5. Close theDate & Time window.

Changing the local time zone

If you have transported your computer to another time zone and want to display the new local time, you must change the time zone designation, not the time display itself, in order to maintain proper synchronization with the network time server.

Note: Do not attempt to manually adjust either the Current Date or Current Time fields. They will be automatically and correctly reset by steps below. 

If you have already chosen to synchronize with a network time server, the system will bar you from resetting the date or time by hand.

  1. From the Apple Menu, open the System Preferences window.

  2. Click the Date & Time icon in the System section of the window.

  3. In the Date & Time window, click the Time Zone tab.

  4. As noted above the world map, "Click your part of the world and then choose a time zone from the pop-up menu."
    For example, users in Manchester, England would click "United Kingdom" from the resulting pop-up menu.

  5. Close the Date & Time window.

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