How Daylight Saving Time Affects Start Times and End Times - Metasys - LIT-12011942 - Software Application - ODS Server - 10.1

Metasys Open Data Server Help

Brand
Metasys
Product name
ODS Server
Document type
User Guide
Document number
LIT-12011942
Version
10.1
Revision date
2019-10-14
Language
English

If daylight saving time is used at your facility, the Profile reacts accordingly. For example, when daylight saving time begins, the system clock on the supervisory controller advances from 1:59 A.M. to 3:00 A.M. If an hourly tracking period is used, the Profile starts a new tracking period at that moment, setting the Current Start Time to 3:00 A.M. and the Current End Time to 4:00 A.M. The Profile also changes the Previous Start Time to 1:00 A.M. and the Previous End Time to 3:00 A.M. The previous profile indicates that 2 hours have elapsed, but contains only 1 hour of energy data.

When daylight saving time ends, the system clock on the supervisory controller changes from 1:59 A.M. to 1:00 A.M. In this scenario, the system does not reach 2:00 A.M. until 2 hours after 1:00 A.M. The current profile contains 2 hours of profile data, even though the Current Start Time is 1:00 A.M. and the Current End Time is 2:00 A.M.

Whereas start/end date and times are not affected when the other tracking periods are used (daily, weekly, monthly, or manual), the period in which daylight saving time begins always contains 1 hour of data fewer than in a standard period. The period in which daylight saving time ends always contains 1 hour of data more than a standard period.