Mark Harris [off-list ref] writes:

For glibc, all 64-bit platforms, and the most recently added 32-bit
platforms (arc, riscv32, or1k), use 64-bit time_t.  All older but
still-supported 32-bit platforms (arm, csky, hppa, m68k, microblaze,
mips, powerpc, s390, sh, sparc, x86) currently use 32-bit time_t by
default but can use 64-bit time_t with -D_TIME_BITS=64.  For musl, all
platforms use 64-bit time_t.

Thanks for the details.

I had looked into it and it seemed that time_t was 32-bits where
__WORD_SIZE == 32.  But it seems I missed the newer 32-bit platforms.

Collin