The Year 2038 problem: when 32-bit Unix time runs out

A signed 32-bit integer can count to 2,147,483,647. As a Unix timestamp, that is the second before the number overflows.

The numbers

A signed 32-bit integer holds values from -2,147,483,648 to 2,147,483,647. Used as seconds since the epoch, the largest value is 2147483647, which is 2038-01-19T03:14:07Z. One second later the counter does not fit. In the usual two's-complement arithmetic it wraps around to -2,147,483,648, which a program reads as 1901-12-13T20:45:52Z. The values above were calculated with Python when this page was built.

Who is affected

• Software and devices that store time in a signed 32-bit integer: older embedded systems, some file formats and database columns, old code in C that uses a 32-bit time_t.
• Software with long-term dates: a loan, a certificate or a subscription that ends after 2038 is already past the limit today.
• Not affected: systems that use 64-bit time. A signed 64-bit count of seconds lasts about 292 billion years.

Modern 64-bit operating systems and most current languages use 64-bit time. The risk lies in old systems, small devices that will stay in service for many years, and data formats with 32-bit fields.

How to check your own systems

1. Find where timestamps are stored. Database column types (INT against BIGINT or TIMESTAMP with a wide range), file formats, protocol fields, and device firmware.
2. Test with a future date. Set a test system's date to a time after 19 January 2038 and see what happens to logins, certificates, schedules and reports. Do this on a test machine, not on a production system.
3. Search the code for 32-bit integer types holding time values.
4. Ask suppliers of embedded devices and old software about their plan.

How to fix

• Use 64-bit integers or a date-time type with a wide range.
• For databases, change INT timestamp columns to BIGINT, or to the database's own date-time type (check its range).
• Update software and firmware.
• Record dates after 2038 in tests.

An unsigned 32-bit number

Using an unsigned 32-bit integer (values from 0 to 4,294,967,295) pushes the limit to 7 February 2106, but you lose the ability to represent dates before 1970.

Common mistakes

1. Believing that the problem is a single moment in 2038. It already affects anything that handles dates after 2038.
2. Believing that nothing runs on 32-bit time any more.
3. Fixing the database but not the file format or the device.

This is an independent guide. It is not connected with the IERS, BIPM, IANA, NIST or any company named here. Facts were read on 14 November 2026 from the sources named on each page; calculated values come from Python.