timespec(3type)

✨ timespec — your girl's guide to time in seconds AND nanoseconds 💅

okay so bestie, welcome to timespec(3type), the manual page itself 🌸 this is a 3type page, which means it's all about a type you can use in your C code, and I'm about to make it make sense. no cap.

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📚 LIBRARY

Standard C library (that's libc, queen 👑)

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🎀 SYNOPSIS

#include <time.h>

struct timespec {
    time_t     tv_sec;   /* Seconds */
    /* ... */  tv_nsec;  /* Nanoseconds [0, 999'999'999] */
};

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💖 DESCRIPTION

So like, a timespec describes times in seconds and nanoseconds. That's the whole vibe. Seconds + nanoseconds, together, holding hands 🫶

Now let's talk tv_nsec, because she's the interesting one. She's of an implementation-defined signed type capable of holding the specified range. Under glibc, this is usually long, and on X32 it's long long. The good news? It can be safely down-cast to any concrete 32-bit integer type for processing. So you can go ahead and narrow her down, she won't break, it's chill 😌

ngl the "implementation-defined" part is the important bit — don't go assuming she's always the exact same type everywhere, because she is not 💀

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🌈 VERSIONS

Prior to C23, tv_nsec was long. so bestie if you're reading old code, that's the tea ☕

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⭐ STANDARDS

C11, POSIX.1-2024. she's got credentials, periodt 💅✨

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🦋 HISTORY

POSIX.1-1996. vintage. iconic. she's been around 👑

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👑 NOTES

The following headers also provide this type, so you might get timespec even if you didn't ask for it directly — sneaky little fairy 🧚:

• <aio.h>
• <mqueue.h>
• <sched.h>
• <signal.h>
• <sys/select.h>
• <sys/stat.h>

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🔥 SEE ALSO

• clock_gettime(2)
• clock_nanosleep(2)
• nanosleep(2)
• timerfd_gettime(2)
• timer_gettime(2)
• time_t(3type)
• timeval(3type)

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okay that's the whole page and you ATE it 💖 this little gem comes from Linux man-pages 6.20, dated 2026-02-08 — go forth and measure some nanoseconds, bestie, I'm obsessed 🎀✨