Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.
We recommend using Visual Studio 2017

Time Management

 

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at Time Management.

Use these functions to get the current time and convert, adjust, and store it as necessary. The current time is the system time.

The _ftime and localtime routines use the TZ environment variable. If TZ is not set, the run-time library attempts to use the time-zone information specified by the operating system. If this information is unavailable, these functions use the default value of PST8PDT. For more information on TZ, see _tzset; also see _daylight, timezone, and _tzname.

Time Routines

FunctionUse.NET Framework equivalent
asctime, _wasctime, asctime_s, _wasctime_sConvert time from type struct tm to character string. The versions of these functions with the _s suffix are more secure.System::DateTime::ToLongDateString, System::DateTime::ToLongTimeString, System::DateTime::ToShortDateString, System::DateTime::ToShortTimeString, System::DateTime::ToString
clockReturn elapsed wall-clock time for process.Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.
ctime, _ctime32, _ctime64, _wctime, _wctime32, _wctime64, _ctime_s, _ctime32_s, _ctime64_s, _wctime_s, _wctime32_s, _wctime64_sConvert time from type time_t, __time32_t or __time64_t to character string. The versions of these functions with the _s suffix are more secure.System::DateTime::GetDateTimeFormats, System::DateTime::ToString, System::DateTime::ToLongTimeString, System::DateTime::ToShortTimeString
difftime, _difftime32, _difftime64Compute difference between two times.System::DateTime::Subtract
_ftime, _ftime32, _ftime64,_ftime_s, _ftime32_s, _ftime64_sStore current system time in variable of type struct _timeb or type struct``__timeb64 The versions of these functions with the _s suffix are more secure.System::DateTime::Now
_futime, _futime32, _futime64Set modification time on open fileSystem::IO::File::SetLastAccessTime, System::IO::File::SetLastWriteTime, System::IO::File::SetCreationTime
gmtime, _gmtime32, _gmtime64, gmtime_s, _gmtime32_s, _gmtime64_sConvert time from type time_t to struct tm or from type __time64_t to struct tm.The versions of these functions with the _s suffix are more secure.System::DateTime::UtcNow, System::DateTime::ToUniversalTime
localtime, _localtime32, _localtime64, localtime_s, _localtime32_s, _localtime64_sConvert time from type time_t to struct tm or from type __time64_t to struct tmwith local correction. The versions of these functions with the _s suffix are more secure.System::DateTime::ToLocalTime
_mkgmtime, _mkgmtime32, _mkgmtime64Convert time to calendar value in Greenwich Mean Time.System::DateTime::ToUniversalTime
mktime, _mktime32, _mktime64Convert time to calendar value.System::DateTime::DateTime
_strdate, _wstrdate, _strdate_s, _wstrdate_sReturn current system date as string. The versions of these functions with the _s suffix are more secure.Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.
strftime, wcsftime, _strftime_l, _wcsftime_lFormat date-and-time string for international use.System::DateTime::ToLongDateString, System::DateTime::ToLongTimeString, System::DateTime::ToShortDateString, System::DateTime::ToShortTimeString, System::DateTime::ToString
_strtime, _wstrtime, _strtime_s, _wstrtime_sReturn current system time as string. The versions of these functions with the _s suffix are more secure.System::DateTime::ToLongDateString, System::DateTime::ToLongTimeString, System::DateTime::ToShortDateString, System::DateTime::ToShortTimeString, System::DateTime::ToString
time, _time32, _time64Get current system time as type time_t, __time32_t or as type __time64_t.Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.
_tzsetSet external time variables from environment time variable TZ.Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.
_utime, _utime32, _utime64, _wutime, _wutime32, _wutime64Set modification time for specified file using either current time or time value stored in structure.Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.
System_CAPS_ICON_note.jpg Note

In all versions of Microsoft C/C++ except Microsoft C/C++ version 7.0, and in all versions of Visual C++, the time function returns the current time as the number of seconds elapsed since midnight on January 1, 1970. In Microsoft C/C++ version 7.0, time returned the current time as the number of seconds elapsed since midnight on December 31, 1899.

System_CAPS_ICON_note.jpg Note

In versions of Visual C++ and Microsoft C/C++ before Visual C++ 2005, time_t was a long int (32 bits) and hence could not be used for dates past 3:14:07 January 19, 2038, UTC. time_t is now equivalent to __time64_t by default, but defining _USE_32BIT_TIME_T changes time_t to __time32_t and forces many time functions to call versions that take the 32-bit time_t. For more information, see Standard Types and comments in the documentation for the individual time functions.

Run-Time Routines by Category

Show: