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Local Clock(s), DST

The Local Clock feature allows for maintaining one or several local times. These times will reflect a time offset, thereby accounting for Time Zone, and DST (Daylight Savings Time) correction.

Adding a Local Clock

To add a Local Clock:

  1. Navigate to MANAGEMENT > OTHER: Time Management.
  2. Click the PLUS icon in the Local Clocks panel in the Time Management screen.
  3. The Local Clock pop-up window will display.
  4. Enter a Name for your local clock.
    • The name must be between 1 and 64 characters long; spaces are allowed.
    • The name can be any meaningful name that helps you know your point of reference (for example: “NewYork”, “Paris” or “EasternHQ”, etc.).
    • This name will be used as cross-reference drop-down in the applicable Input or Output port configuration. Please note the following limitations apply to this option:

      Note: Acceptable characters for the name include: A-Z, a-z, 0-9, (-+_) and space.

  5. In the UTC Offset field, choose a UTC Offset from the drop-down list.
    • All of the UTC Offset drop-down selections are configured as UTC plus or minus a set number of hours.
    • Examples for the US: For Eastern, choose UTC–05:00; for Central, choose UTC-06:00; for Mountain, choose UTC-07:00; and for Pacific, choose UTC-08:00.
    • If you wish to use DST (Daylight Savings Time ["Summer Time"]) rules, click the Use DST Rules box. Otherwise the time for the local clock will always be standard time.

      DST options will appear in the Local Clock window:

  6. Set DST Rules by Region: Check this box to apply regional DST rules. A regions drop-down menu with the following options will display:
    • EU (Europe): For locations complying with the European DST Rule. This rule differs from all other rules because the DST changes occur based on UTC time, not local time (all time zones in Europe change for DST at precisely the same time relative to UTC, rather than offset by local time zone).

    • US-Canada: For locations complying with the USA’s DST Rule (as it was changed to back in 2006, where the “DST into” date is the Second Sunday of March and the “DST out” date is the first Sunday of November).

    • Australia.

    • Note: If a pre-configured rule DST rule happens to be changed in the future (like the change to the US DST rule in 2006), this option allows the DST rules to be edited without the need to perform a software upgrade for a new DST rule to be defined. Select this drop-down and enter the DST parameters for the new rule.

  7. DST Start Date and DST End Date: This option is provided for locations that do not follow any of the pre-configured DST rules. Click anywhere in either field to open a calendar, allowing you to enter any custom day & time rule.
  8. Offset: In seconds. Use this field to manually define your local clock’s DST offset e.g., 3600 seconds for a one hour offset.
  9. DST Reference: When configuring a Local Clock that is synchronized to an input reference (e.g., IRIG input), VersaSync needs to know the timescale of the input time (Local Timescale, or UTC Timescale), in order to provide proper internal conversion from one Timescale to another.
    Select Local or UTC, depending on the Timescale of the Input reference this Local Clock is being used with.
    Additional Local Clocks may need to be created if multiple input Timescales are being submitted.
  10. Click Submit. Your local clock will appear in the Local Clocks panel.

DST Examples

The following two examples illustrate the configuration of Daylight Savings Time (DST) for a Local Clock:

Example 1:

To create a Local Clock to UTC+1 with no DST rule:

1.  Navigate to MANAGEMENT > Time Management: Local Clocks > (+): Local Clock.

2.  In the Local Clock Name field, assign a meaningful name to the new Local Clock.

3.  From the UTC Offset pull down menu, select “UTC +01:00”.

4.  Confirm that the Use DST Rules checkbox is not selected.

5.  Review the changes made and click the Submit button.

The unit will display the status of the change.

Example 2:

To create a Local Clock for a VersaSync installed in the Eastern Time Zone of the US, and desiring the Local Clock to automatically adjust for DST (using the post 2006 DST rules for the US).

1.  In the MANAGEMENT > Time Management: Local Clocks > (+): Local Clock window:

2.   Navigate to MANAGEMENT > Time Management: Local Clocks > (+): Local Clock.

3.  From the UTC Offset pull-down menu, select “UTC -05:00”.

4.  Select the Use DST Rules checkbox.

5.  Select the Set DST Rules by Region checkbox.

6.  From the DST Region drop-down list, select “US-Canada.”

7.  Review the changes made and click the Submit button.

The unit will display the status of the change.


Neither UTC, nor GMT ever change to Daylight Savings Time (DST). However, some of the countries that use GMT switch to a different time zone offset during their DST period. The United Kingdom is not on GMT all year, but uses British Summer Time (BST), which is one hour ahead of GMT, during the summer months.

Additional information about regional time zones and DST can be found on the following web sites:,