# Sigma Computing: Incorrect timestamps returned from warehouse for some customers

- Impact (vendor’s label): major
- Status: postmortem
- Started: 2023-08-14 17:34 UTC · Resolved: 2023-08-07 17:32 UTC · Duration: -10082 min
- Updates: 2
- [Vendor status page: https://stspg.io/whwz9w0wpcfx](https://stspg.io/whwz9w0wpcfx)
- [Company: Sigma Computing](https://rewindex.com/company/sigma-computing.md)

## Summary

Sigma Computing reported a major incident affecting some customers: warehouse timestamps were off by their UTC offset, and date\_trunc() could return incorrect values due to code refactoring. The recorded start is 2023-08-14 17:34 UTC, but resolution is dated earlier, 2023-08-07 17:32 UTC; duration is unknown. _(machine-written, sol)_
## Timeline of updates

- **resolved** 2023-08-07 17:32 UTC: Backdated Incident: Some customers observed that timestamps in data returned from the warehouse were incorrect. Specifically the timestamp was off by the UTC offset (hours the customer timezone is ahead or behind UTC). Customers may have also observed that date\_trunc() would return incorrect values. This was due to a change made during a code refactoring; no behavioral difference was anticipated, but certain customer configurations experienced the described discrepancy. Impacted Cloud Regions & Services: Snowflake  and DataBricks customers with a particular combination of timezone configuration in Sigma and their warehouse were impacted by this issue.  Note the refactored code path was enabled for some customers on August 7, and then progressively enabled for more customers and warehouses over several days; notably: - August 8, 17:30 UTC, code path enabled for all Databricks customers - August 10, 15:58 UTC, code path enabled for all Snowflake customers  - August 10, 18:49 UTC, code path disabled for all Snowflake customers - August 14, 15:40 UTC, code path disabled for all customers Incident Start Time: 2023-08-07 18:10 UTC Incident End Time: 2023-08-14 15:40 UTC We will perform a root cause analysis (RCA) and publish our findings in a postmortem note to the Sigma Community site in coming days.
- **postmortem** 2023-10-06 20:44 UTC: Sigma Engineering has completed the postmortem of this incident. A Root Cause Analysis \\(RCA\\) is available on the Sigma Community site: \[Postmortem for Aug 10th, 2023: Incorrect results for timezone-based calculations\](https://community.sigmacomputing.com/t/postmortem-for-aug-10th-2023-incorrect-results-for-timezone-based-calculations/2618)

## Rewindex changes for this incident

- 2023-08-14 17:34 UTC: [Major incident: Incorrect timestamps returned from warehouse for some customers](https://rewindex.com/change/i1ed3209523bf86.md)


---
Canonical: https://rewindex.com/company/sigma-computing/incidents/p55zyhhvgbfq · Markdown: https://rewindex.com/company/sigma-computing/incidents/p55zyhhvgbfq.md · JSON: https://rewindex.com/api/v1/companies/sigma-computing/incidents/p55zyhhvgbfq · Generated 2026-10-18T12:19:42.182Z