# Missing is not zero

English reference summary. Updated 2026-09-26. Reference facts checked 2026-09-07. Author: Oleksii Shevchenko, SHEV Software.
Canonical article: https://www.enerplain.com/notes/missing-is-not-zero/

This is an invented teaching fixture, not customer or OEM data. One fictional device is expected to report interval energy in kWh every 15 minutes, including overnight. Timestamps label interval start. Window: [2026-10-25T00:00:00Z, 2026-10-25T02:00:00Z).

Expected intervals: 8. Observed source records: 7. Source observations are zero-valued. Application records: 8. The absent source record at 2026-10-25T00:30:00Z has been filled with a downstream zero.

Observed source subtotal: 0.00 kWh. Complete source-window total: unknown (JSON null). A downstream filler cannot establish the missing observation. The source absence, its cause, eventual arrival and equipment condition cannot be established from this fixture.

[Inspect the JSON](https://www.enerplain.com/examples/missing-is-not-zero.json).