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std::put_time

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< cpp‎ | io‎ | manip
 
C++
 
Input/output library
 
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(C++20)  

Status flags manipulation
Time and money I/O
(C++11)
(C++11)
(C++11)
put_time
(C++11)
Quoted manipulator
(C++14)
 
Defined in header <iomanip>
template< class CharT >
/*unspecified*/ put_time( const std::tm* tmb, const CharT* fmt );
 (since C++11)

When used in an expression out << put_time(tmb, fmt), converts the date and time information from a given calendar time tmb to a character string according to format string fmt, as if by calling std::strftime, std::wcsftime, or analog (depending on CharT), according to the std::time_put facet of the locale currently imbued in the output stream out.

Contents

[edit] Parameters

tmb - pointer to the calendar time structure as obtained from std::localtime or std::gmtime
fmt - pointer to a null-terminated CharT string specifying the format of conversion

[edit] Format string

The format string consists of zero or more conversion specifiers and ordinary characters (except %). All ordinary characters, including the terminating null character, are copied to the output string without modification. Each conversion specification begins with % character, optionally followed by E or O modifier (ignored if unsupported by the locale), followed by the character that determines the behavior of the specifier. The following format specifiers are available:

Conversion
specifier 		Explanation Used fields
% writes literal %. The full conversion specification must be %%.
n
(C++11) 		writes newline character
t
(C++11) 		writes horizontal tab character
Year
Y writes year as a decimal number, e.g. 2017 tm_year
EY
(C++11) 		writes year in the alternative representation, e.g.平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale tm_year
y writes last 2 digits of year as a decimal number (range [00,99]) tm_year
Oy
(C++11) 		writes last 2 digits of year using the alternative numeric system, e.g. 十一 instead of 11 in ja_JP locale tm_year
Ey
(C++11) 		writes year as offset from locale's alternative calendar period %EC (locale-dependent) tm_year
C
(C++11) 		writes first 2 digits of year as a decimal number (range [00,99]) tm_year
EC
(C++11) 		writes name of the base year (period) in the locale's alternative representation, e.g. 平成 (Heisei era) in ja_JP tm_year
G
(C++11) 		writes ISO 8601 week-based year, i.e. the year that contains the specified week.

In ISO 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:

  • Includes January 4
  • Includes first Thursday of the year
tm_year, tm_wday, tm_yday
g
(C++11) 		writes last 2 digits of ISO 8601 week-based year, i.e. the year that contains the specified week (range [00,99]).

In ISO 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:

  • Includes January 4
  • Includes first Thursday of the year
tm_year, tm_wday, tm_yday
Month
b writes abbreviated month name, e.g. Oct (locale dependent) tm_mon
h
(C++11) 		synonym of b tm_mon
B writes full month name, e.g. October (locale dependent) tm_mon
m writes month as a decimal number (range [01,12]) tm_mon
Om
(C++11) 		writes month using the alternative numeric system, e.g. 十二 instead of 12 in ja_JP locale tm_mon
Week
U writes week of the year as a decimal number (Sunday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OU
(C++11) 		writes week of the year, as by %U, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
W writes week of the year as a decimal number (Monday is the first day of the week) (range [00,53]) tm_year, tm_wday, tm_yday
OW
(C++11) 		writes week of the year, as by %W, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
V
(C++11) 		writes ISO 8601 week of the year (range [01,53]).

In ISO 8601 weeks begin with Monday and the first week of the year must satisfy the following requirements:

  • Includes January 4
  • Includes first Thursday of the year
tm_year, tm_wday, tm_yday
OV
(C++11) 		writes week of the year, as by %V, using the alternative numeric system, e.g. 五十二 instead of 52 in ja_JP locale tm_year, tm_wday, tm_yday
Day of the year/month
j writes day of the year as a decimal number (range [001,366]) tm_yday
d writes day of the month as a decimal number (range [01,31]) tm_mday
Od
(C++11) 		writes zero-based day of the month using the alternative numeric system, e.g. 二十七 instead of 27 in ja_JP locale

Single character is preceded by a space.

tm_mday
e
(C++11) 		writes day of the month as a decimal number (range [1,31]).

Single digit is preceded by a space.

tm_mday
Oe
(C++11) 		writes one-based day of the month using the alternative numeric system, e.g. 二十七 instead of 27 in ja_JP locale

Single character is preceded by a space.

tm_mday
Day of the week
a writes abbreviated weekday name, e.g. Fri (locale dependent) tm_wday
A writes full weekday name, e.g. Friday (locale dependent) tm_wday
w writes weekday as a decimal number, where Sunday is 0 (range [0-6]) tm_wday
Ow
(C++11) 		writes weekday, where Sunday is 0, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
u
(C++11) 		writes weekday as a decimal number, where Monday is 1 (ISO 8601 format) (range [1-7]) tm_wday
Ou
(C++11) 		writes weekday, where Monday is 1, using the alternative numeric system, e.g. 二 instead of 2 in ja_JP locale tm_wday
Hour, minute, second
H writes hour as a decimal number, 24 hour clock (range [00-23]) tm_hour
OH
(C++11) 		writes hour from 24-hour clock using the alternative numeric system, e.g. 十八 instead of 18 in ja_JP locale tm_hour
I writes hour as a decimal number, 12 hour clock (range [01,12]) tm_hour
OI
(C++11) 		writes hour from 12-hour clock using the alternative numeric system, e.g. 六 instead of 06 in ja_JP locale tm_hour
M writes minute as a decimal number (range [00,59]) tm_min
OM
(C++11) 		writes minute using the alternative numeric system, e.g. 二十五 instead of 25 in ja_JP locale tm_min
S writes second as a decimal number (range [00,60]) tm_sec
OS
(C++11) 		writes second using the alternative numeric system, e.g. 二十四 instead of 24 in ja_JP locale tm_sec
Other
c writes standard date and time string, e.g. Sun Oct 17 04:41:13 2010 (locale dependent) all
Ec
(C++11) 		writes alternative date and time string, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
x writes localized date representation (locale dependent) all
Ex
(C++11) 		writes alternative date representation, e.g. using 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale all
X writes localized time representation, e.g. 18:40:20 or 6:40:20 PM (locale dependent) all
EX
(C++11) 		writes alternative time representation (locale dependent) all
D
(C++11) 		equivalent to "%m/%d/%y" tm_mon, tm_mday, tm_year
F
(C++11) 		equivalent to "%Y-%m-%d" (the ISO 8601 date format) tm_mon, tm_mday, tm_year
r
(C++11) 		writes localized 12-hour clock time (locale dependent) tm_hour, tm_min, tm_sec
R
(C++11) 		equivalent to "%H:%M" tm_hour, tm_min
T
(C++11) 		equivalent to "%H:%M:%S" (the ISO 8601 time format) tm_hour, tm_min, tm_sec
p writes localized a.m. or p.m. (locale dependent) tm_hour
z
(C++11) 		writes offset from UTC in the ISO 8601 format (e.g. -0430), or no characters if the time zone information is not available tm_isdst
Z writes locale-dependent time zone name or abbreviation, or no characters if the time zone information is not available tm_isdst

[edit] Return value

An object of unspecified type such that

  • if out is an object of type std::basic_ostream<CharT, Traits>, the expression out << put_time(tmb, fmt)
    • has type std::basic_ostream<CharT, Traits>&
    • has value out
    • behaves as if it called f(out, tmb, fmt)

where the function f is defined as: 

template<class CharT, class Traits>
void f(std::basic_ios<CharT, Traits>& str, const std::tm* tmb, const CharT* fmt)
{
    using Iter = std::ostreambuf_iterator<CharT, Traits>;
    using TimePut = std::time_put<CharT, Iter>;
 
    const TimePut& tp = std::use_facet<TimePut>(str.getloc());
    const Iter end = tp.put(Iter(str.rdbuf()), str, str.fill(), tmb,
        fmt, fmt + Traits::length(fmt));
 
    if (end.failed())
        str.setstate(std::ios_base::badbit);
}

[edit] Example

Run this code
#include <ctime>
#include <iomanip>
#include <iostream>
 
int main()
{
    std::time_t t = std::time(nullptr);
    std::tm tm = *std::localtime(&t);
 
    std::cout.imbue(std::locale("ru_RU.utf8"));
    std::cout << "ru_RU: " << std::put_time(&tm, "%c %Z") << '\n';
 
    std::cout.imbue(std::locale("ja_JP.utf8"));
    std::cout << "ja_JP: " << std::put_time(&tm, "%c %Z") << '\n';
}

Possible output: 

ru_RU: Ср. 28 дек. 2011 10:21:16 EST
ja_JP: 2011年12月28日 10時21分16秒 EST

[edit] See also

 formats contents of std::tm for output as character sequence
(class template) [edit]
(C++11)
 parses a date/time value of specified format
(function template) [edit]
converts a std::tm object to custom textual representation
(function) [edit]
converts a std::tm object to custom wide string textual representation
(function) [edit]
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