-D_TIME_BITS=64 -D_FILE_OFFSET_BITS=64
#include <stdio.h>
#include <time.h>
int main () {
printf("__TIMESIZE value is: %d\n", __TIMESIZE);
printf("time_t size is: %d bit\n", sizeof(time_t) * 8);
printf("__time64_t size is: %d bit\n", sizeof(__time64_t) * 8);
return 0;
}
On a system with __TIMESIZE == 32 the output will be:
__TIMESIZE value is: 32
time_t size is: 32 bits
__time64_t size is: 64 bit
__TIMESIZE value is: 32
time_t size is: 64 bit
__time64_t size is: 64 bit
Conclusion
The Y2038 issue is is important but not yet a big problem but would be a wise idea to start planning, triaging, and testing before it becomes urgent.