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Can somebody explain Daylight Saving (DST) impact on OOZie scheduling ?

Daylight Saving and OOZie workflow scheduling.

What is day light saving ?

- Daylight saving is used by few countries only, where they re-set their clocks twice in a year as below.

1. Clock Forwarding : (1:59 AM Clock will go to 3:00 AM)

On 09-Mar-2014 is the day on which clock will be forwarded by 1 Hour.

As soon as Clock reaches 1:59 AM on (09-Mar-2014) , your clock will be set to 3:00 AM. So you will never have 2:00 AM 09-Mar-2014 to 2:59 AM 09-Mar-2014 in clock.

2. Clock Reset : (1:59 AM Clock will reset to 1:00 AM again)

On 02-Nov-2014 is the day on which clock will be reset back by 1 Hour.

As soon as Clock reaches 1:59 AM On (02-Nov-2014) , your clock will be set to 1:00 AM. So you will have time between 1:00 AM to 1:59 twice.

Impact on scheduling : (If it is sheduled between clock reset time)

Example : Lets assume you have scheduled cycle to run everyday 2:30 AM. 

What happen on 09-Mar-2014 ?

Ans : We will miss this cycle to run on 02-Mar-2014 

Because as soon as clock reaches 1:59 AM on 2-Mar-2014, it will be forwarded by one hour and next time will be 3:00 AM on 09-Mar-2014.  

 

Example : Lets assume you have scheduled cycle to run everyday 1:30 AM. 

What happen on 02-Nov-2014 ?

Ans : Cycle will be executed twice on 02-Nov-2014 

Because as soon as clock reaches 1:59 AM on 2-Nov-2014, it will be reset back by one hour and next time will be 1:00 AM on 09-Mar-2014.  Hence, there will be 1:30 AM twice.

 

Practically :

- On 09-Mar-2014 you will have 23 hours of day.

- On 02-Nov-2014 you will have 25 hours of day. 

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0 # DST is done every yearHadoopExam.com 2016-07-20 09:47
Most of the United States begins Daylight Saving Time at 2:00 a.m. on the second Sunday in March and reverts to standard time on the first Sunday in November. In the U.S., each time zone switches at a different time.
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