C Date and time utilities

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Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros(C++20)
Language support library
Concepts library(C++20)
Diagnostics library
Memory management library
Metaprogramming library(C++11)
General utilities library
Containers library
Iterators library
Ranges library(C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library(C++17)
Concurrency support library(C++11)
Execution control library(C++26)
Technical specifications
Symbols index
External libraries

Time zone
tzdb (C++20)
tzdb_list (C++20)
get_tzdbget_tzdb_listreload_tzdbremote_version (C++20)(C++20)(C++20)(C++20)
sys_info (C++20)
local_info (C++20)
nonexistent_local_time (C++20)
ambiguous_local_time (C++20)
locate_zone (C++20)
current_zone (C++20)
time_zone (C++20)
choose (C++20)
zoned_traits (C++20)
zoned_time (C++20)
time_zone_link (C++20)
leap_second (C++20)
leap_second_info (C++20)
get_leap_second_info (C++20)
C-style date and time

C-style date and time utilities

Defined in header`<ctime>`
Time manipulation
difftime	computes the difference between times (function)[edit]
time	returns the current time of the system as time since epoch (function)[edit]
clock	returns raw processor clock time since the program is started (function)[edit]
timespec_get (C++17)	returns the calendar time in seconds and nanoseconds based on a given time base (function)[edit]
Format conversions
asctime	converts astd::tm object to a textual representation (function)[edit]
ctime	converts astd::time_t object to a textual representation (function)[edit]
strftime	converts astd::tm object to custom textual representation (function)[edit]
wcsftime	converts astd::tm object to custom wide string textual representation (function)[edit]
gmtime	converts time since epoch to calendar time expressed as Universal Coordinated Time (function)[edit]
localtime	converts time since epoch to calendar time expressed as local time (function)[edit]
mktime	converts calendar time to time since epoch (function)[edit]

number of processor clock ticks per second
(macro constant)[edit]

tm	calendar time type (class)[edit]
time_t	time since epoch type (typedef)[edit]
clock_t	process running time (typedef)[edit]
timespec (C++17)	time in seconds and nanoseconds (struct)[edit]