Better (subjective?) C/C++ __DATE__ (Mmm dd yyyy) macro that adds a zero to dd instead of the default space if the value is less than 10.

__DATE__.c

#define BUILD_DATE (const char[]) { \
    __DATE__[0], __DATE__[1], __DATE__[2], __DATE__[3], \
    (__DATE__[4] == ' ' ?  '0' : __DATE__[4]), __DATE__[5], \
    __DATE__[6], __DATE__[7], __DATE__[8], \
    __DATE__[9], __DATE__[10], '\0' \
}

// Use:
// printf("%s\n", BUILD_DATE);