Dateshifting

Dateshifting is a general term for intentionally changing calendar dates associated with data, events or publications. It is not a single standardized technique but a family of practices used in different fields for different purposes, including privacy protection, scheduling, marketing and record management.

In data privacy and research, dateshifting (also called date perturbation or date offsetting) modifies timestamps in datasets so exact calendar dates cannot be linked to individuals while preserving relative intervals. Typical methods include adding a fixed offset, applying a random offset within a defined window, or shifting by a consistent patient-level offset. This helps reduce re-identification risk but can degrade temporal accuracy for analyses that depend on absolute dates.

In media and publishing, dateshifting can describe changing release or publication dates for strategic, regulatory or distribution reasons. In operations and project management, it may refer to rescheduling activities by moving dates forward or backward to manage workload or dependencies.

Implementation choices balance utility and protection: larger or random offsets increase privacy but reduce fidelity; consistent offsets preserve within-subject timing but may leak linking information if not combined with other safeguards. Legal and ethical considerations vary by jurisdiction and sector; some regulatory frameworks set specific de-identification guidance.

Related concepts include time-shifting (viewing or recording media at a different time), date stamping, and anonymization techniques. Practical use requires assessing impact on data quality, compliance and intended downstream uses.