Daylight Saving Time and the LI-7550 Analyzer Interface Unit

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Description of how the LI-7550 handles daylight savings time.

Daylight Saving Time

Daylight Saving Time (DST) is the practice of setting the clocks forward one hour near the start of spring and back again in autumn in order to make better use of the daylight in the evenings. This practice is adopted in some regions but not others. You can find out whether or not, and how, DST is implemented in your area through a Google search on the Internet.

DST Setting on the LI-7550

The LI-7550 Analyzer Interface Unit running embedded software versions 4.1.1, 4.1.2, 4.1.3, 5.0.1, 5.0.3, 6.0.0, 6.5.0, 7.0.1, and 7.3.0 automatically adjusts the clock for DST based on the time zone users have selected. The embedded software automatically determines whether or not DST is adopted in a time zone. For example, for U.S. Eastern Standard Time, the LI-7550 clock automatically changes to 1:00 am at 2:00 am on March 8 and to 3:00 pm at 2:00 pm on November 1 in 2015. If DST is not adopted in a region (such as in China), the clocks do not change.

Influence on Data Logging

When an automatic clock adjustment for DST occurs on the LI-7550, 1) all time stamps in the data records will shift one hour forward from the start to the end of DST, and 2) one hour of data will be lost prior to the start of DST.