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The site idea
Backwards Risk
A future deadline starts to matter when a system must look or live past it. That moment is earlier than the deadline by whatever forward horizon the system uses.
risk_entry = deadline − forward_horizon
A forward horizon is not a metaphor. It is a number already written down somewhere: equipment lifetime, certificate validity, retention period, maintenance plan, booking window, support contract, loan term.
Worked Unix example
Deadline: 19 January 2038. Horizon: 10 years of industrial service life.
Risk-entry date: 19 January 2028. Any 10-year box installed after that date is sold into a life that includes the overflow, whether or not the firmware has a 64-bit clock.
| Horizon | Unix Y2038 risk-entry |
|---|---|
| 30 years | 2008-01-19 |
| 25 years | 2013-01-19 |
| 20 years | 2018-01-19 |
| 15 years | 2023-01-19 |
| 12 years | 2026-01-19 |
| 10 years | 2028-01-19 |
| 7 years | 2031-01-19 |
| 5 years | 2033-01-19 |
| 3 years | 2035-01-19 |
Do not invent a lifetime. Use the figure the vendor, insurer or maintenance contract already uses. If you do not have one, the calculator still lets you try ranges.
Why this is the useful page
Searchers type “how long until 2038”. Operators need “does this PLC, meter, or car ECU still have a 32-bit clock, and will it still be in service?” The first question is a countdown. The second is Backwards Risk plus an evidence record.