On 5/31/21 9:01 AM, Adhemerval Zanella via Libc-alpha wrote:
> It is on 2.34 plan [1], Carlos O'Donnel is reviewing it.  Similar to LFS,
> you will need a newer flag to actually enable it (-D_TIME_BITS=64).

One place where Microsoft got it right and we're arguably getting it 
wrong, is that 64-bit time_t is the default on 32-bit MS-Windows, where 
one must opt into 32-bit by #defining _USE_32BIT_TIME_T.

It's too late in 2.34 to make 64-bit time_t the default, but we should 
at least document that 64-bit time_t is planned to be default in the 
future. That is, programmers should not *rely* on 32-bit being the default.

Obviously 64-bit will have to be the default eventually. (Rumors of x86 
dying out completely before 2038 are exaggerated; some 32-bit software 
will likely live on past 2038 even if 32-bit-only chips are no longer 
made.) We should warn developers about that now.

Since making 64-bit time_t the default also means 64-bit off_t will be 
the default, we should warn developers about that too.

Proposed patch attached, relative to the azanella/y2038 branch.