Keep the lesson for the next incident
Write timestamp contracts
Document each timestamp's meaning, accepted input form, storage representation, precision, and display or grouping zone. Name date-only fields explicitly and state whether they represent a calendar label or an instant. Keep source-specific exceptions adjacent to the contract they qualify.
Retain edge fixtures
Keep compact examples for midnight, positive and negative offsets, daylight-saving transitions, month ends, and precision cutoffs. Assert expected membership and display results. Choose fixtures from the incident when possible, and include one negative example that must remain outside a boundary.
Set calendar review
Assign ownership for business-time policy and implementation checks. Review boundary samples across relevant seasons or source changes, and define a trigger for new offsets or shifted totals. Close the follow-up only after the documented contract and observed outputs agree for the covered calendar.
What to carry forward
Close the learning record with timestamp contracts, edge fixtures, policy ownership, and a recurrence review that can expose a shifted boundary. Keep unsupported source zones listed as open work. The lasting improvement is shared time semantics backed by examples, not a blanket reliance on one default zone.
Keep the decision with the work.
Use a Work Item in Aglet to record the problem, the evidence you have, and the next decision. Add an owner and priority, then keep updates in the discussion so the next person can follow the reasoning.
Create an account See the product workflow