Debian 13 and the year 2038

Computers record time in a time_t type. On 32-bit systems, the traditional 32-bit signed time_t can only count up to 19 January 2038 before it overflows — the "year 2038 problem" (Y2038), essentially the millenium bug all over again, but for timekeeping.

How Debian 13 fixes it

Debian 13 moves every architecture except i386 to a 64-bit time_t, so dates well beyond 2038 are represented correctly. From the release announcement:

All architectures other than i386 now use a 64-bit time_t ABI, supporting dates beyond 2038.

The most visible impact is on 32-bit ARM hardware (armhf, single-board computers in particular): from Debian 13 on, system time on these devices is no longer bounded by 2038, so NTP synchronisation, certificate validity checks and scheduled jobs all keep working past 2038.

One ABI change — what to watch for

A 64-bit time_t changes the C binary interface (ABI) on 32-bit architectures:

• Regular users need to do nothing — every package in the Debian 13 archive is built against the new ABI and upgrades as one piece
• Self-compiled 32-bit programs must be rebuilt in a Debian 13 environment; they cannot mix with old 32-bit time_t binaries
• Third-party closed-source 32-bit ARM programs need a vendor build against the new ABI

Verify the time_t size

Compile and run this on a 32-bit Debian 13 system (armhf, for example):

/* sizeof_time.c */
#include <stdio.h>
#include <time.h>

int main(void) {
    printf("sizeof(time_t) = %zu bytes\n", sizeof(time_t));
    return 0;
}

gcc sizeof_time.c -o sizeof_time && ./sizeof_time
# On Debian 13 armhf: sizeof(time_t) = 8 bytes (4 bytes on Debian 12)

Next steps

• Debian 13 hub - back to the release overview
• Hardware compatibility - what hardware is supported
• Download Debian 13 - pick the architecture for your device