difftime(3)

💖 NAME 💖

okay bestie, say hi to difftime — she calculates the time difference ✨

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📚 LIBRARY 📚

Standard C library, aka libc, and you link her with -lc 🎀

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✨ SYNOPSIS ✨

#include <time.h>

double difftime(time_t time1, time_t time0);

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🌸 DESCRIPTION 🌸

so difftime() hands you back the number of seconds that elapsed between the time time1 and the time time0, and it gives it to you as a double 💅 each of those times is literally just a count of seconds, no cap.

and here's the iconic part: difftime(b, a) acts like (b-a), EXCEPT the result does not overflow and it's rounded to double. the way she protects you from overflow?? main character energy 👑

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🦋 ATTRIBUTES 🦋

for the whole explanation of the terms used down here, go peek at attributes(7) 🫶

• Interface: difftime()
• Attribute: Thread safety
• Value: MT-Safe

so yeah, she's thread safe, she can hang with everybody at once, no drama 💜

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⭐ STANDARDS ⭐

C11, POSIX.1-2008 ✨

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🌈 HISTORY 🌈

POSIX.1-2001, C89, SVr4, 4.3BSD — she's been around, she's vintage, she's an icon 💖

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👑 SEE ALSO 👑

date(1), gettimeofday(2), time(2), ctime(3), gmtime(3), localtime(3)

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okay that's the whole page, bestie 🎀 this one came from Linux man-pages 6.20, dated 2026-02-08, and yeah the page you're on is difftime(3) 🦋 go time-diff something, ily, bye 💅🌸