DST change doesnt apply to data in replicate target task

[danielrf]

Hi,

We have a task that picks data from oracle source to postgres target. During the DST Daylight Saving Time last weekend of March 2025, it seems the data in the postgres target is still in winter time (1 hour + utc ) and it should be 2 hour + utc. And we need to do a full reload to make the dates show properly.

I checked the documentation it looks the DST wont impact unless we were in the midle of a full load during the change or scheduling.

https://help.qlik.com/en-US/replicate/November2023/Content/Global_Common/Content/SharedEMReplicate/D...

This is not our case, we just ran the task for months without touching anything. The DST change happens while CDC is running.

The data type  in oracle source is TIMESTAMP WITH LOCAL TIME ZONE, replicate picks by default as string and we cast as datetime(6) in qlik replicate, in postgres the data type is TIMESTAMP

I suspect the issue is caused due we store in pg the timestamp without timezone ( data type is just timestamp and not timestampz) and this is an example of data content :  2025-03-11 14:09:24

Could it be the root cause ? I understand that if we dont store the +1 during the winter and we dont store the +2 during summer, postgres wont be able to detect the diference during DST changes? that makes sense to me, but does make sense to qlik replicate?

Does Qlik Replicate is able to recognize de data from Oracle source with local time zone as UTC? (as it is stored in reality in oracle source)

[john_wang]

Hello @danielrf ,

Thanks for reaching out to Qlik Community!

To better understand and troubleshoot the behavior, we kindly request the following additional information:

1. Time Zone and Time Settings for all three servers involved:

   • Source database

   • Replicate server

   • Target database

2. Time Zone Configuration at the Database Level for both the source and target databases.

3. Sample Data Records from both the source and target sides for comparison.

4. Table DDLs (for both source and target), including primary key and unique index definitions.

5. Task Diagnostics Package — Please attach the full diagnostics package for the task. Depending on our analysis, we may request you to increase the logging level of certain components. Our support engineer will guide you through that if needed.

Kindly open a support ticket and include the requested details and diagnostics. Our support team will be happy to assist you further.

Best Regards,

John.

[danielrf]

Thanks John,

I suspect the issue is caused due we store in pg the timestamp without timezone ( data type is just timestamp and not timestampz) and this is an example of data content :  2025-03-11 14:09:24

Could it be the root cause ? I understand that if we dont store the +1 during the winter and we dont store the +2 during summer, postgres wont be able to detect the diference during DST changes? that makes sense to me, but does make sense to qlik replicate?

Does Qlik Replicate is able to recognize de data from Oracle source with local time zone as UTC? (as it is stored in reality in oracle source)

[john_wang]

Hello @danielrf ,

I'm not very sure which step led the issue that's why we need a support ticket to move it forward.

Please share the ticket number if you get it.

thanks,

John.