A potentially major problem with OSX Compiling

[PinkPlague]

So, I every time I run make in the terminal it spits out these errors.

src/gfx/window.c:69:25: warning: implicit declaration of function 'timespec_get' is invalid in C99 [-Wimplicit-function-declaration]
    window.last_frame = NOW();
                        ^
src/gfx/../util/time.h:11:5: note: expanded from macro 'NOW'
    timespec_get(&ts, TIME_UTC);\
    ^
src/gfx/window.c:69:25: error: use of undeclared identifier 'TIME_UTC'
src/gfx/../util/time.h:11:23: note: expanded from macro 'NOW'
    timespec_get(&ts, TIME_UTC);\
                      ^
src/gfx/window.c:70:26: warning: implicit declaration of function 'timespec_get' is invalid in C99 [-Wimplicit-function-declaration]
    window.last_second = NOW();
                         ^
src/gfx/../util/time.h:11:5: note: expanded from macro 'NOW'
    timespec_get(&ts, TIME_UTC);\
    ^
src/gfx/window.c:70:26: error: use of undeclared identifier 'TIME_UTC'
src/gfx/../util/time.h:11:23: note: expanded from macro 'NOW'
    timespec_get(&ts, TIME_UTC);\
                      ^
src/gfx/window.c:158:25: warning: implicit declaration of function 'timespec_get' is invalid in C99 [-Wimplicit-function-declaration]
        const u64 now = NOW();
                        ^
src/gfx/../util/time.h:11:5: note: expanded from macro 'NOW'
    timespec_get(&ts, TIME_UTC);\
    ^
src/gfx/window.c:158:25: error: use of undeclared identifier 'TIME_UTC'
src/gfx/../util/time.h:11:23: note: expanded from macro 'NOW'
    timespec_get(&ts, TIME_UTC);\
                      ^
3 warnings and 3 errors generated.
make: *** [src/gfx/window.o] Error 1

I was hoping to get this to work, but sadly I do not posses enough knowledge in C# to be able to find the problem. Good luck!

[TheTechRobo]

(By the way, this is not C#, this is C.)

What OS X version are you on?