C timespec milliseconds. h 库的 clock() 函数 1.

C timespec milliseconds This function takes two arguments: a clock ID and a pointer to a timespec struct, which will be filled with the current time. 10 2024-05-02 timespec Feb 7, 2025 · The declaration order of tv_sec and tv_nsec is unspecified. POSIX-y calls like pselect() and clock_gettime() use struct timespec. Data Type: struct timespec ¶ struct timespec represents a simple calendar Yes, this can be achieved using the clock_gettime() function. Then the two fields are added together to get the total number of milliseconds since 1970. h' and has the following members: long int tv_sec This represents the number of whole seconds of elapsed time. You can calculate elapsed time after you capture the start and stop times. Because problem is that time difference between two events is mostly is zero seconds. 1-2008. If you need millisecond precision, though, the most portable way is to call timespec_get. Under glibc, this is usually long, and long long on X32. I did not get zero. 678'. Table of Dec 11, 2008 · As of ANSI/ISO C11 or later, you can use timespec_get() to obtain millisecond, microsecond, or nanosecond timestamps, like this: Nov 11, 2015 · Im working with the clock_gettime() command and trying to append a given amount of milliseconds to the timespec that I get from it. * Set seconds and nanoseconds field of a timespec variable and * normalize to the timespec storage format * Note: The tv_nsec part is always in the range of 0 <= tv_nsec < NSEC_PER_SEC. I am using difftime which returns me the time in seconds. The function is called gettimeofday() and you can look at the man page to find out what to include and how to use it. I have tried following code for the same. h> struct timespec { time_t tv_sec; long tv_nsec; } Description: The timespec structure specifies a time in seconds and nanoseconds. Mar 17, 2019 · I want to convert milliseconds into timespec structure used by GNU Linux. This special extension was Aug 16, 2021 · The clock_gettime function requires a struct timespec object as an argument. C11 doesn't mandate that struct tm has a subsecond component, and strftime() has no way to format subsecond Apr 29, 2013 · I have this program which prints the time difference between 2 different instances, but it prints in accuracy of seconds. long int tv_nsec The GNU C Library does not provide any functions for computing the difference between two values of type struct timeval or struct timespec. tv_nsec to the number of milliseconds times one million, or convert from std::chrono::milliseconds to std::chrono::nanoseconds. Where the second hadn't changed from the last time, they just added a random value between 1 and 200 to millisec (making sure it didn't go past 999 of course - the actual max for the rand() was always the min of 200 May 13, 2023 · Aside from coding the call in Assembly (which may not show any improvements), I modified the code to use two timespec structures. h> int timespec_get(struct timespec *ts, int base); If base is TIME_UTC, the tv_sec member is set to the number of seconds since an implementation defined epoch, truncated to a whole value and the tv_nsec member is set to the integral number of nanoseconds, rounded to the resolution of the system clock Nov 7, 2022 · Real arithmetic type capable of representing times. The values are, auto: When the value is auto, the time component will be printed in HH:MM:SS format. g. The GNU C Library additionally guarantees that time_t is a signed type, and that all of its functions operate correctly on negative time_t values, which are interpreted as times before the epoch. Please help me. Calculate Elapsed Time in a Code Block in C Using the gettimeofday Function. tv_nsec Apr 30, 2022 · Call the function enough times that you get total time in the seconds, and use any method to measure (even plain C clock()). For Example, Input: Current system time. See Time Types , for a description of struct timespec . tv_sec = second; rqtp. It works even on some peculiar operating systems where the tv_sec member has an unsigned type. tv_nsec / 1000000; With gettimeofday() (which is officially deprecated, but is more widely available — for example, Mac OS X has gettimeofday() but does not have clock_gettime() ), you have a struct In order to support applications requiring much more precise pauses (e. 2. 7k次。本文深入探讨了Linux系统中时间与日期的处理方法，包括UNIX纪元、time_t数据类型、timespec结构体、时间转换函数如time、difftime、gmtime、localtime，以及时间格式化函数如strftime和strptime的使用。 Apr 19, 2017 · With the code beneath I can get the current time in milliseconds. h&gt; header file and the programmer has used the Sl Jun 16, 2023 · I searched a lot but there are either structs holding the wall time without milliseconds, or structs returning the current time in milliseconds that I have to convert into wall time separately, or functions that return seconds and milliseconds in extra fields which would be ok to use but isn't what I'd call elegant. Apr 17, 2019 · How to measure execution time for a C17 program, how to delay the program for a specified amount of time Function: int clock_gettime (clockid_t clock, struct timespec *ts) ¶ Get the current time according to the clock identified by clock , storing it as seconds and nanoseconds in * ts . Also, gettimeofday() should be avoided. Aug 27, 2024 · C语言显示毫秒的几种方法包括：使用time. C11で採用されたらしい新しい時間構造体。 Jan 25, 2019 · to produce milliseconds. Jul 11, 2017 · C11 does specify a struct timespec (§7. If microseconds component is available it will be printed. h>`头文件中的`clock_gettime()`函数来获取高精度的时间戳，包括毫秒级别。这个函数返回的是`struct timespec`类型的值，其中包含了自纪元（通常是1970年1月1日）以来的秒数和纳秒数。 Data Type: struct timespec The struct timespec structure represents an elapsed time. 23 Nov 11, 2022 · double timespec_delta2milliseconds(struct timespec *last, struct timespec *previous) { struct timespec delta = sub_timespec(*last, *previous); return timespec_to_double_milliseconds(delta); } You can use an extra value in the function so it is easier to print the value returned in a debugger: double rv = timespec_to_double_milliseconds(delta In C, you can use the POSIX function clock_gettime() to get the current time with high precision. It can be safely down-cast to any concrete 32-bit integer type for processing. Measuring in micro/nanoseconds is inherently too imprecise. Oct 12, 2023 · C++ で時間をミリ秒単位で取得するには time() 関数を使用する. How to print milliseconds in C? 9. Sep 26, 2014 · I have a program (mixed C and Fortran, although that doesn't seem to be relevant) that uses nanosleep. If you need to handle negative offsets (negative values for ms ), you have more work to do, dealing with negative results tv_nsec after adding a May 28, 2024 · In this article, we will learn how to get time in milliseconds in C++. isoformat(sep=' ', timespec='milliseconds') leads to '2021-12-08 20:00:00. – Mar 17, 2014 · C libraries have a function to let you get the system time. c (in case no implementation is available) and as various system-dependent implementations elsewhere. C++ でシステム時刻を取得するもう一つの POSIX 準拠の方法は、time 関数を呼び出すことです。 Feb 12, 2023 · In a timespec, tv_sec is a time_t type, which is 32 bits or 64 bits in length depending on whether the preprocessor macro _USE_32BIT_TIME_T is defined. You have two fields both of which must be converted to milliseconds. [] NoteThe type of tv_nsec is long long on some platforms, which is currently non-conforming in C++, but is allowed in C since C23. Dec 27, 2021 · timespec_get (C11) returns the calendar time in seconds and nanoseconds based on a given time base (function) C++ documentation for time. h>: struct timespec { time_t tv_sec; /* seconds */ long tv_nsec; /* nanoseconds */ }; Dec 17, 2014 · It is hard to know without seeing your exact code. The type is a struct with two fields: struct timespec { time_t tv_sec; long If you're using C11 not on a Linux or POSIX system, you'll need to replace clock_gettime() in those functions with timespec_get(). 000+00:00" # milliseconds print(has_microseconds(a)) print(has_microseconds(b Mar 5, 2025 · #include <time. c This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. 962" && date --rfc-3339=ns Note the delay: CURTIME=`date --rfc-3339=ns` date --set="${CURTIME}" NEWTIME=`date --rfc-3339=ns` echo ${CURTIME} echo ${NEWTIME} 2011-12-07 01:48:54. Calling it, however, takes a bit more effort because it involves a struct. the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC. Prior to C23, tv_nsec was long. 5 The timespec_get function function, which is isomorphic to clock_gettime() — it does the same job but is in Standard C rather than POSIX. The tv_nsec value ca Seeing @dbush's answer is exactly what I needed to see to learn how to convert Linux timestamps to usable local times!. Is the truncation specified in ISO standard or is it just a bug? May 24, 2019 · namespace std {int timespec_get (struct timespec * ts, int base);} 概要 指定したベース時間に基づいた、経過秒と経過ナノ秒を取得する。 This gives you the time taken in milliseconds with a precision of microseconds. Jul 10, 2015 · 일반적으로 시간을 구하는 함수는 많은데, 일반적으로 그 정밀도가 수십 밀리세컨드로 정밀한 시간차이를 구하기 위해서 사용하기에는 적절하지 않습니다. from datetime import datetime def has_microseconds(dt): return not datetime. Jun 22, 2013 · Measure time in milliseconds for C code on windows. org Linux man-pages 6. However, if my timespec has a tv_sec value of 0, it simply doesn't sleep. Data Type: struct timespec ¶ The struct timespec structure represents an elapsed time. %09ld UTC\n", buff, ts. : #include <time. To review, open the file in an int myNanosleep(int second, int millisecond) { struct timespec rqtp = {}; struct timespec rmtp = {}; rqtp. tv_nsec); printf("Raw timespec. Try Teams for free Explore Teams 4 days ago · some *nix system functions (e. tv_sec)); printf("Current time: %s. Here is the recommended way to do this calculation by hand. POSIX. Apr 8, 2022 · I'm basically trying to set a timer to wait for a specified amount of seconds from the current time. Thanks in Jul 24, 2018 · The timespec_get function's implementation depends on the system the library is running on, so it appears both as a stub in time/timespec_get. Oct 24, 2013 · In Java, we can use System. 0. C11, POSIX. Jan 18, 2025 · このプログラムでは、timespec_get()関数を用いて処理の開始時間と終了時間を取得し、その差を計算することで経過時間を求めています。 timespec構造体の理解. long int tv_nsec Apr 2, 2022 · This looks cleaner than the [:-3] in the accepted answer, but you should know that it seemingly does the same >>> datetime. See the result below. I want to print it in milliseconds and another in nanoseconds difference. Jun 24, 2014 · Convert struct timespec to a uint64_t number of nanoseconds since epoch and take deltas between those and accumulate them easily. tv_nesc += (milli*1000000); Oct 14, 2021 · Thanks jonnin. poll(), C. Although not defined by the C standard, this is almost always an integral value holding the number of seconds (not counting leap seconds) since 00:00, Jan 1 1970 UTC, corresponding to POSIX time. E. To get the time in milliseconds we can use the methods of <chrono> library. Sep 18, 2016 · The correct way to measure time is to use clock_gettime(CLOCK_MONOTONIC, &ts_current);. tv_nsec); } Feb 20, 2016 · So if your compiler and libraries is compliant to C11 2, you might use timespec_get() and possibly get a system dependent precision up to nanoseconds (or even greater than 1 second). 000000+00:00" # microseconds c = "2018-07-13T00:00:00. I know that timespec's tv_sec only includes whole numbers. Oct 17, 2016 · The functions clock_gettime() and clock_settime() retrieve and set the time of the specified clock clk_id. 03 [Linux/C 언어] 멀티캐스트 송신 코드 및 테스트 (Multicast Sender) 2021. timespec GetTimeSpecValue(unsigned long milisec) { struct timespec req; Feb 7, 2025 · timespec_get (& ts, TIME_UTC); char buff [100]; strftime(buff, sizeof buff, "%D %T", gmtime(& ts. C Code: Sleep in Milliseconds using nanosleep - CodePal Free cookie consent management tool by TermsFeed Mar 11, 2025 · C/C++ Solutions for Handling Accurate Time Using struct timespec in C99. Nov 10, 2015 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. h&gt; int main (int a Learn how to write a C function that sleeps for a specified number of milliseconds using the nanosleep function. 26 [C 언어] 시리얼 통신 Open 함수 (struct termios) 2021. isoformat(timespec='seconds') == dt a = "2018-07-13T00:00:00+00:00" # seconds b = "2018-07-13T00:00:00. fromisoformat(dt). md)関数によって返される、エポックからの経過時間を表す型である。 各メンバ変数は、以下を意味する： Toggle navigation Aug 13, 2022 · C provides difftime to figure out the number of seconds and timegm is helpful for the UTC timezone. The first 2 rows is just to show the foruml C言語で現在時刻をミリ秒単位で取得するには、time. tv_nsec = millisecond * 1000 * 1000; return nanosleep(&rqtp, &rmtp); } のような関数を書けば、秒単位・ミリ秒単位で実行を停止させることができます。 Mar 10, 2015 · First of all, you generally shouldn't do this sort of thing. Jul 14, 2015 · What is the best destination and how to get there from a struct timespec or struct timeval since that is an easy transformation and micro seconds is good enough for these timings? I presume that I want to be getting to this, right? std::chrono::system_clock::time_point. h库的clock()函数、使用gettimeofday()函数、使用C11标准的timespec_get()函数。 本文将对这三种方法进行详细介绍，并列举其优缺点。 一、使用 time. 720541318+00:00 保有时长的结构体，拆分成秒和纳秒。 成员对象 Apr 12, 2013 · There are a few different UNIX time formats, but if you want to convert your time in milliseconds into a C/POSIX timespec with nanoseconds, rather than the obsolete formats in <sys/time. * * Returns a normalised version of a timespec structure, according to the * following rules: * * 1) If tv_nsec is >=1,000,000,00 or <=-1,000,000,000, flatten the surplus * nanoseconds into the tv_sec field. I am converting it to run on Red Hat Linux. struct timespec timespec_from_timeval(struct timeval tv) Converts a timeval to a timespec. The members include: tv_sec The number of seconds. We’ll first create a Unix epoch which corresponds to seconds since January 1st 1970 at 00:00:00 UTC. In this article, we’ll explore how to calculate elapsed time in a code block using C. The function to get the current time in a struct timespec is timespec_get(). It also works in C++17. The struct timespec is part of the POSIX standard and is available since C99, designed to accurately represent time with seconds and nanoseconds. https://linux. #include <time. The source code has included the &lt;windows. I think it's really just a matter of API [in]compatibility. struct timespec timespec_from_ms(long milliseconds) Converts an integer number of milliseconds to a timespec. Here's an example of how you can use clock_gettime() to get the current time in milliseconds: Converts a timespec to a fractional number of seconds. It is declared in time. May 24, 2019 · `timespec`は、[`timespec_get()`](timespec_get. timespec_get() timespec_get()用来将当前时间转成距离时间纪元的纳秒数（十亿分之一秒）。 int timespec_get (struct timespec * ts, int base ); timespec_get()接受两个参数。 第一个参数是 struct timespec 结构指针，用来保存转换后的时间信息。struct timespec 的结构如下。 struct timespec Jan 16, 2024 · C11 and later has the §7. This represents the number of whole seconds of elapsed time. And yes, they are using Jun 4, 2014 · Is there a way to get milliseconds precision, accurate (at least within a few ms) times in C using a cross-platform approach? on a POSIX system I can use sys/time. Measuring time in mili or microseconds in C Language. clock_gettime 함수는 리눅스 환경에서 코딩할때 특정 구간내에서 실행되는 코드의 정밀한 시간차를 구하려고 할 때 사용할 수 있는 함수 입니다 Here is a solution (Linux, NOT Unix):date --set="2011-12-07 01:20:15. tv_nsec: %09ld\n", ts. 1-2001. tv_sec * INT64_C(1000) + t. Here is the code: 2023_05_13-Lesson-b. In the current version of POSIX, gettimeofday() is marked obsolete. h>) which is compatible with POSIX struct timespec and supports nanosecond resolution. but I want to calculate the time in milliseconds. A complete example of using clock_gettime() to measure time difference (both seconds and nanoseconds, which you could convert to milliseconds): Mar 10, 2025 · Fetch the time with timespec_get(). It is useful as an unambiguous, easy-to-work-with representation of a point in time. Implementation may add other data members to timespec. Describes times in seconds and nanoseconds. The res and tp arguments are timespec structures, as specified in <time. tv_sec); printf("Raw timespec. Jan 1, 2020 · enum { milliseconds_per_second = 1000, nanoseconds_per_second = 1000000000, nanoseconds_per_millisecond = nanoseconds_per_second / milliseconds_per_second }; I'm not sure whether that's worth it. So I'm struggling what to do if I nee Jan 13, 2021 · '프로그래밍 언어/C언어' Related Articles [C 언어] 프로그램이 read 에서 멈출때 해결법(read() 타임 아웃 설정:select) 2021. h). It gives me a value. It is declared in `time. h>, set . As a quick refresher, timespec is a type defined in the ctime header (aka time. 3. h 库的 clock() 函数 1. Watch out for that tricky tm_mon element (number of months since January, so August is really 7 not 8). End Microsoft Specific Mar 17, 2009 · I want to calculate the time difference between two events in C++ in milliseconds. In C programming, the gettimeofday function is a powerful tool for obtaining accurate time Oct 20, 2019 · 文章浏览阅读2. Hi I want to calculate the time difference between two events in C++ in milliseconds. Now I want to add milliseconds to the systemtime. … Aug 30, 2024 · C语言如何打印当前毫秒时间戳 在C语言中，获取和打印当前的毫秒时间戳主要依赖于系统提供的时间相关函数。使用gettimeofday函数、使用clock_gettime函数、使用C++的<chrono>库（需混合编程）。下面将详细介绍如何通过这几种方法来实现获取当前毫秒时间戳，并提供一个完整的代码示例。 一、…. clock() 函数的使用 clock() 函数是C… Dec 22, 2024 · 在Linux环境下，C语言可以使用`<time. h> #include <stdint. The timespec type can be used to store either a time interval or absolute time. But timespec contains: std::time_t tv_sec and long tv_nsec I have no problem with tv_nsec since it is a long number, so (time1. Feb 12, 2024 · In C, you can achieve this by using various functions provided by the standard library. Firstly "seconds" (tv_sec) which must be multiplied by 1000, and secondly nano-seconds (tv_nsec) which must be divided by 1000000. 687216122+00:00 2011-12-07 01:48:54. 1 Date and time <time. tv_nsec is of an implementation-defined signed type capable of holding the specified range. We will also represent the epoch in milliseconds, as a double, and finally convert to an ISO 8601 Timestamp. Output: Current time in milliseconds since epoch: 1716440609637 Get Current Time in Milliseconds. 678900'). It can tell time up to nanosecond precision, if the system supports. die. Aug 2, 2016 · The standard C library provides the time function and it is useful if you only need to compare seconds. Nov 8, 2018 · I'm relatively new to C programming and I'm working on a project which needs to be very time accurate; therefore I tried to write something to create a timestamp with milliseconds precision. h> #include <sys/time. Jan 31, 2019 · timespec Refresher; Conversion Functions; Bonus: timeval conversions; Further Reading; timespec Refresher. If specifying an absolute time, this member is the number of seconds since 1970. This way I could call the clock_gettime() function twice in a row, hopefully to obtain a tighter nanosecond interval. , in order to control some time-critical hardware), nanosleep() would handle pauses of up to 2 milliseconds by busy waiting with microsecond precision when called from a thread scheduled under a real-time policy like SCHED_FIFO or SCHED_RR. h> inline uint64_t as_nanoseconds(struct timespec* ts) { return ts->tv_sec * (uint64_t)1000000000L + ts->tv_nsec; } int main() { struct timespec start, stop; uint64_t accu_nsec = 0; for () { // record start // perform some timespec - Format specifier for the timespec. Any hints? #include <stdio. In this case, the timespec is UNIX time from a GPS. timespec構造体は、timespec_get()関数で使用されるデータ型で、以下の2つのメンバを持ちます。 Among the timing functions, time, clock getrusage, clock_gettime, gettimeofday and timespec_get, I want to understand clearly how they are implemented and what are their return values in order to k timespec_diff. h, but that is not cross-platform Nov 2, 2010 · I am working on logger using C language on QNX platform using Momnetics to print time in following format 2010-11-02 14:45:15. However guesses might include: you neglected to convert the clock ticks to a known unit such as nanoseconds. \$\endgroup\$ – kbro Commented Jan 14, 2024 at 15:43 Feb 8, 2023 · I need a way to get the time in a high precision (milliseconds or microseconds) for a PRNG algorithm I'm writing in C (C11), as time(0) is not precise enough. 02. 27. Here are some additional tips for measuring time in milliseconds using ANSI C: Use the clock() function instead of the time() function, as it provides better precision. In C, you can use the POSIX function clock_gettime() to get the current time with high precision. I tried using several other possible Jul 13, 2018 · Assuming you are dealing with datetime string in iso format. This is an Optional Parameter with a dfault value of "auto". . Mar 29, 2014 · #include <time. We’ll conclude with the challenge of using fractional seconds. hライブラリのclock_gettime関数やgettimeofday関数を使用します。 これらの関数は、システムクロックからの時間をナノ秒またはマイクロ秒単位で取得し、それをミリ秒に変換することで実現します。 Aug 3, 2024 · timespec_get 函数是内联函数，如果定义了 _USE_32BIT_TIME_T，将调用 _timespec32_get；否则调用 _timespec64_get。 End Microsoft Specific 默认情况下，此函数的全局状态范围限定为应用程序。 Mar 12, 2019 · time_t is an absolute time, represented as the integer number of seconds since the UNIX epoch (midnight GMT, 1 January 1970). Timestamps in C In this post I’ll provide some ways to create, convert and print timestamps using C. Jul 21, 2009 · I have some source code that was compiled on Windows. 结构体成员变量的单位是秒和纳秒，因此在进行计算时需要注意单位转换； timespec只适用于持续时间和时间戳等没有时区概念的场景，无法表示跨越多个时区的时间; 特殊的timespec常量在头文件中预定义，如{0, 1000000}表示1毫秒。 We would like to show you a description here but the site won’t allow us. , like this: Fri Apr 15 14:05:12 2022 -0700. But I want more precision in milliseconds. Nov 13, 2023 · The timespec structure provides the ability to specify timestamps with up to nanosecond precision: struct timespec { time_t tv_sec; // Seconds since Unix epoch long tv_nsec; // Nanoseconds }; The tv_sec field contains the number of seconds since the Unix epoch (January 1, 1970). I'm not sure how widely available timespec_get() is. struct timeval timespec_to_timeval(struct timespec ts) Converts a timespec to a timeval. epoll_wait()) accept an int value as timeout in milliseconds with the special value -1 meaning "infinite" fn (Duration) timespec # fn ( d Duration ) timespec ( ) C . Various filesystem calls like utimes(), and some assorted Linux calls like gettimeofday() and select(), use struct timeval. h and has the following members: time_t tv_sec. net/man/3/clock_gettime In the date and time utilities section of the C 次に紹介するstruct timespecと非常によく似た構造体である。 tv_sec time()の戻り値と同値。 tv_usec 範囲は0～999,999; gettimeofday()によってUNIX時間を表現した値が入ったインスタンスが取得できる。 構造体timespec. c May 16, 2012 · As for precision, the docs say that you get the precision of the underlying data type, so if you have a chrono::milliseconds type then you get milliseconds. h> struct timespec t; clock_gettime(CLOCK_REALTIME, &t); int64_t millitime = t. 03. C. <chrono> provides a type-safe and generic units library for handling time durations, and there are few good reasons to escape this safety and genericity. 000 I able to get date, hour, minutes, and seconds using time(&amp; 1）修改timespec指向的对象以ts在时基中保存当前日历时间base。 2）扩展为适合用作 base 参数的值 timespec_get 其他的宏常量 TIME_ 可以由实现提供，以指示附加的时基。 May 10, 2024 · 四、timespec的注意事项. This means it may be removed from a future version of the specification. The resolution of clocks depends on the implementation and cannot be configured by a particular process. Mar 9, 2015 · A friend of mine (not me of course) once used a similar trick - they kept statics containing the last second and "millisecond". The timespec_get function is an inline function that calls _timespec32_get if _USE_32BIT_TIME_T is defined; otherwise it calls _timespec64_get. The function clock_getres() finds the resolution (precision) of the specified clock clockid, and, if res is non-NULL, stores it in the struct timespec pointed to by res. I took it further though and printed the timestamp output in more ways, including in human-readable strings with day, month, year, etc. tv_nsec)*1e-3; would be correct. timespec Dec 19, 2012 · ref: linux clock_gettime I found a formula which works well to get the processing time, but there's something I don't understand. Can I just do this? //milli is an int that can be any number (within reason) struct timespec ts; clock_gettime(CLOCK_REALTIME, &ts); ts. 2 main timestamp functions in C: C11: timespec_get() is part of the C11 or later standard, but doesn't allow choosing the type of clock to use. Use the CLOCK_MONOTONIC macro to get a more accurate time measurement, if available. currentTimeMillis() to get the current timestamp in Milliseconds since epoch time which is -. c语言没有c++那样强大的时间值运算库（chrono）。但是时间戳（timespec）的运算是非常常用的操作，所以这个问题必须妥善的解决。 BSD的解决方案BSD操作系统同规定了一些操作时间戳（timespec）的的函数： // time. fromisoformat('2021-12-08 20:00:00. tv_sec: %jd\n", (intmax_t) ts. Does a time struct like this If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up- to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to man-pages@man7. hamjxlzj wokvul ctqgpjp pnims mehxp mlzi ngzr pemfybis afct fgtmofmm oviib ywn jple xbinnw igkjcx