Daylight Savings Time: changes for 2007

Overview

The DST operating system patches released in early 2007 for Windows and Macintosh are designed to update the OS so it will compute the correct Greenwich Mean Time Offset (GMT Offset) based on computer location and date. These patches are necessitated by changes in 2007 to the Daylight Savings Time (DST) changeover dates for locations in the US, Canada, and Mexico. Without these OS patches, time displayed on a computer in these locations will be off by one hour during the few weeks, spring and fall, when the new versus old changeover dates differ¹. Without these OS patches, any date and time information displayed during these periods by a K2 component will likewise be off by an hour (unless the GMT Offset has been manually adjusted to the corrected value).

Whenever a particular K2 component displays a time, it is always displayed in the ”local time“ representation, based on the current location and time setting values of the computer which is running the component. With a few exceptions detailed below², whenever the location setting for a computer is correctly configured and its clock is showing the correct local time, then any K2 component will correctly interpret, store, and display date and time information. Since all K2 version 6.1 components³ make use of ”Coordinated Universal Time“ (UTC) for internal storage of date and time information, it is important that any computer running a K2 component is configured with the correct GMT Offset (based on time zone and Daylight Savings status for the particular location and date). This can be assured by applying the DST patches to the OS so that its time synchronization services will work automatically and correctly.

¹ The new changeover date in 2007 for Daylight time to begin (US, Canada, Mexico) is March 11 (three weeks earlier than in previous years). The new changeover date in 2007 to revert back to standard time (US, Canada, Mexico) is Nov. 4 (one week later than in previous years).

² The K2 Server, Reporter, and Admin components include DST change over date information internally. Updates to these components released in 2007 accurately support the new changeover dates - either through updates to the internal data (Win) or through calls to new OS services (Mac). If older versions of these components (hosted in the US, Canada, or Mexico) make reference to times within the spring and fall periods mentioned above, there may be a 1 hour discrepancy in referencing or saving UTC time data, even when the host computer has correct location and time settings (e.g. even if the GMT Offset is correct).

³ KeyCheckout version 6.0 does not store times in UTC format, unlike all other 6.0 and 6.1 components. To avoid time zone problems, don't use the old KeyCheckout 6.0 (and of course, make sure the local time, DST status, and location are correct on the client computer).
 

Avoiding DST and time zone issues

Any computer using any K2 component should be maintained with the correct GMT Offset (which will change by plus or minus one hour at every DST transition, spring and fall). This is most easily accomplished by applying the DST operating system patches for the new 2007 changeover times. Then with a correct location setting, the correct GMT Offset will be maintained automatically by the operating system.

Assuming the GMT Offset is correct:

• KeyServer time synchronization - By default, the KeyAccess client software will allow a user to enable time synchronization to the KeyServer. This time sync feature was introduced years ago before network time servers became ubiquitous. It is usually simplest to avoid concerns by simply disabling this service - in KeyConfigure, use the General Settings item from the Admin menu to select the ”Always turn Time Synchronization Off“ radio button. Otherwise, if you do want to make use of the time sync feature, make sure that the KeyServer process has been updated to the latest release so that it will properly compute local time using the new DST changeover dates.
   
• KeyCheckout and Portable keys - KeyCheckout version 6.1 stores the expiration time for a checked out, portable, key using UTC. This same time convention is used by the KeyServer process for maintaining the corresponding license checkout record. UTC provides the basis for maintaining synchronization of the portable key expiration time regardless of DST and time zone (location) changes on either server or client. To avoid any ”off by one hour“ DST problems, the KeyServer component must be version 6.1.0.8 or better (and of course GMT Offsets must be correct on server and client). Also check the Warnings or Component History documents for other version specific KeyAccess issues.
   
• Time Range selection for Reports - Usage reports are typically run from a specified beginning time to a specified ending time. To avoid possible ”off by one hour“ DST problems, components (KeyServer, KeyConfigure, and/or KeyReporter) should be updated to the 2007 versions which include the latest DST changeover dates.

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