State Data Center Daylight Saving Time 2007 Overview February 15, 2007

Daylight Saving Time 2007 First change in 20 years U.S. Energy Act of 2005 extends Daylight Saving Time (DST) by 4 weeks. First change in 20 years Intended to reduce energy consumption Beginning in 2007, Daylight Saving Time starts 3 weeks earlier and ends one week later. Starts second Sunday in March (March 11, 2007) Was first Sunday in April (April 1, 2007) Ends first Sunday in November (November 4, 2007) Was last Sunday in October (October 28, 2007)

Potential Impact Areas Main areas User calendaring/scheduling functions (Outlook/ GroupWise/Blackberry) Computers and network infrastructure (servers, workstations, routers, etc) Time-sensitive deadlines (filing dates, application submittal times) Time-driven access/functionality (building access, application access)

Potential Impact Areas (cont.) Calendaring applications (including BlackBerry-style devices synching with an e-mail server) showing incorrect meeting schedules.    Incorrect times for arrivals and departures within the travel industry.    Bank transaction errors, manifesting in late payments.    Trading applications executing purchases and sales at the incorrect time.   Missed deadlines for admissions and other time-sensitive enrollment programs. Auctions ending earlier, impacting late bids.    Cell phone and other tariff billing applications incorrectly charging peak rates during non-peak times.    Batch recovery, rollback and job scheduling processes operating off incorrect journal timestamps.    Security programs improperly denying access to IT resources.

Potential Impact Areas (cont.) Building management systems that rotate or automatically exercise equipment by time of day could perform tasks at unexpected times. Security systems that control access by time of day may inappropriately deny or allow access. Logs and time stamps could be incorrect. System events will be difficult to correlate. 

What Should Agencies Do? “Any time-sensitive functions could be impacted by this change. ... It is important for users to assess their environments and develop appropriate plans for applying the necessary changes.” IBM Web site

SDC DST Activities Established DST project team January 2, 2007 Researched, researched, researching Developed action plan Technology Forum with agency staff (February 8) Executing action plan More info later . . .

Computer System Date/Time Basics Most computer systems and networks have internal clocks to keep track of the time. Operating systems generally contain tables of time zone information and local daylight saving transition dates so that the system time can be represented correctly based on the location of the system user. For instance, a user would set up a computer located in California with a home time of Greenwich Mean Time (GMT) 08:00, or 12:00 a.m. Pacific Standard Time. Depending on the date the user sets, the operating system of applications would determine whether the local time should be represented as Daylight Saving Time (adjust the clocks one hour ahead) or Standard Time. Timekeeping for computer applications and systems is typically done in Coordinated Universal Time, or UTC. UTC is a universal standard of representing time that is independent of time zones and based on the old system of deriving local time from GMT. To figure a local time, the operating system or application can take a UTC value, determine what the offset to UTC is based on the time-zone information and then make any adjustments for Daylight Saving Time. Implementations vary and, in some cases, handling of time is reversed-that is, the local clock is used as a basis and the UTC time is derived from it. Differences in how applications store and use time values can create some of the risks and impacts we've discussed. Many computer systems and networks use an external time service for synchronizing time. Governments around the world typically provide time services through official government or scientific clocks available for companies and organizations through an Internet time protocol called Network Time Protocol. System or network administrators can use NTP to synchronize the clocks on their equipment to report time. However, NTP provides a way to synchronize clocks with a reference clock and does not inherently provide a mechanism for accommodating time zone changes and updates.