Events arrive from Japan, the United States, and Europe with different local time zones.
Use one daily-aggregation boundary and avoid daylight-saving-time drift.
Which transformation is most appropriate?
Interpret the input time zone and convert each value to a UTC timestamp column.
Detailed explanation
Using the regional context converts local values to an absolute time and gives downstream aggregation one standard.
Using the regional context converts local values to an absolute time and gives downstream aggregation one standard.
An AWS API audit timestamp does not represent the occurrence time of an external business event.
An AWS API audit timestamp does not represent the occurrence time of an external business event.
A storage class changes cost and access characteristics, not timestamp values.
A storage class changes cost and access characteristics, not timestamp values.
Removing time information loses the ordering and boundaries needed for time-series analysis.
Removing time information loses the ordering and boundaries needed for time-series analysis.
Check official documentation
Compare the following points with the official documentation.
AWS Glue・Sparkのtimestampとタイムゾーン変換、日付パーティションの公式説明を確認する。
What to confirm
文字列削除や保存設定ではなく、タイムゾーンを考慮した日時変換を説明できる。
Key points
- UTC
- Time zone
- Daylight saving time
- Daily aggregation
Notes
- Environment: AWS公式DEA-C01試験ガイドと各サービスの公式ドキュメントの確認
- Confirm current AWS service behavior in the official DEA-C01 documentation.
Foundation review
Storage versus presentation
Store an absolute timestamp consistently and apply a local zone only when displaying or grouping by business time.
Boundary validation
Day changes, daylight transitions, invalid zones, and null values need explicit tests.