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ML Academy

Feature engineering and preprocessing · insight-1123

Build calendar features for each timestamp that drives the outcome, such as booking date and travel date

Evidence type
practitioner heuristic
Difficulty
medium
Roles
Data scientist, Data analyst
Industries
aviation, e-commerce

Summary: situation, action, reason, boundary

  1. Situation

    A booking table has both booking date and departure date, but only departure-date calendar features exist because it is the row key.

  2. Action

    Derive weekday, month and holiday-proximity features for both timestamps plus lead time, then test each family by ablation to see which cycle carries the signal.

  3. Reason

    Buying behaviour and travel demand follow different calendars; each deserves its own seasonality terms rather than sharing one.

  4. Boundary

    Bookings, orders, claims and loans where an event date and a service or maturity date coexist.

Symptom or risk

Two separate cycles, when travellers buy and when they fly, are entangled in one set of calendar columns, so the model cannot separate purchase habits from travel demand.

Exceptions

Same-day products where both timestamps coincide.

Trade-offs

More correlated columns to select among, and lead time must be computed from the decision moment.

Pitfalls

Using the booking date of the final record rather than of the snapshot being predicted.

Lessons and concepts