A fresh API response can contain an old measurement
An environmental data service publishes a temperature reading at noon, but the sensor recorded it at 9 am. Timestamp integrity ensures that users can distinguish observation time from publication time.
Define time fields
Observation, receipt, processing and publication times describe different events.
Use consistent time standards
Document time zones and formats so downstream systems interpret instants correctly.
Protect original timestamps
Delayed uploads should retain the time when measurements occurred.
Check clock synchronisation
Sensor clock drift and gateway configuration can create misleading sequences.
Handle missing time information
Uncertain timestamps should be flagged rather than silently replaced with the current time.
Test across system boundaries
Conversions and API transformations may introduce offsets or formatting errors.
Break-test: a gateway uploads yesterday’s readings today
Can consumers recognise their true age and avoid treating them as live observations?
Connected knowledge
See Stale Data Alerting, Data Freshness Monitoring and NEA.