template <class charT>/*unspecified*/ put_time (const struct tm* tmb, const charT* fmt);
Put date and time
Inserts the representation of the time and date information pointed by tmb, formatting it as specified by argument fmt.

Internally, the function accesses the output sequence by first constructing an object of type basic_ostream::sentry. Then (if evaluating the sentry object is true), it calls time_put::put (using the stream's selected locale) to perform both the formatting and the insertion operations, adjusting the stream's internal state flags accordingly. Finally, it destroys the sentry object before returning.

This manipulator is declared in header <iomanip>.


Pointer to the object of type struct tm with the date and time information to format.
struct tm is a class defined in header <ctime>.
C-string used by time_put::put as format string. It contains any combination of regular characters and special format specifiers. These format specifiers are replaced by the function to the corresponding values to represent the time specified in tmb. They all begin with a percentage (%) sign, and are:
specifierReplaced byExample
%aAbbreviated weekday name *Thu
%AFull weekday name * Thursday
%bAbbreviated month name *Aug
%BFull month name *August
%cDate and time representation *Thu Aug 23 14:55:02 2001
%CYear divided by 100 and truncated to integer (00-99)20
%dDay of the month, zero-padded (01-31)23
%DShort MM/DD/YY date, equivalent to %m/%d/%y08/23/01
%eDay of the month, space-padded ( 1-31)23
%FShort YYYY-MM-DD date, equivalent to %Y-%m-%d2001-08-23
%gWeek-based year, last two digits (00-99)01
%GWeek-based year2001
%hAbbreviated month name * (same as %b)Aug
%HHour in 24h format (00-23)14
%IHour in 12h format (01-12)02
%jDay of the year (001-366)235
%mMonth as a decimal number (01-12)08
%MMinute (00-59)55
%nNew-line character ('\n')
%pAM or PM designationPM
%r12-hour clock time *02:55:02 pm
%R24-hour HH:MM time, equivalent to %H:%M14:55
%SSecond (00-61)02
%tHorizontal-tab character ('\t')
%TISO 8601 time format (HH:MM:SS), equivalent to %H:%M:%S14:55:02
%uISO 8601 weekday as number with Monday as 1 (1-7)4
%UWeek number with the first Sunday as the first day of week one (00-53)33
%VISO 8601 week number (00-53)34
%wWeekday as a decimal number with Sunday as 0 (0-6)4
%WWeek number with the first Monday as the first day of week one (00-53)34
%xDate representation *08/23/01
%XTime representation *14:55:02
%yYear, last two digits (00-99)01
%zISO 8601 offset from UTC in timezone (1 minute=1, 1 hour=100)
If timezone cannot be termined, no characters
%ZTimezone name or abbreviation *
If timezone cannot be termined, no characters
%%A % sign%
* The specifiers marked with an asterisk (*) are locale-dependent.
Two locale-specific modifiers can also be inserted between the percentage sign (%) and the specifier proper to request an alternative format, where applicable:
ModifierMeaningApplies to
EUses the locale's alternative representation%Ec %EC %Ex %EX %Ey %EY
OUses the locale's alternative numeric symbols%Od %Oe %OH %OI %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy
charT is the character type in the c-string.

Return Value

Unspecified. This function should only be used as a stream manipulator (see example).

Errors are signaled by modifying the stream's internal state flags:
failbitThe function failed to format tmb as specified by fmt (it may also be set if the construction of sentry failed).
badbitEither the insertion on the stream failed, or some other error happened (such as when this function catches an exception thrown by an internal operation).
When set, the integrity of the stream may have been affected.
Multiple flags may be set by a single operation.

If the operation sets an internal state flag on the stream that was registered using its member exceptions, the function throws an exception of type ios_base::failure.


// put_time example
#include <iostream>     // std::cout
#include <iomanip>      // std::put_time
#include <ctime>        // std::time_t, struct std::tm, std::localtime
#include <chrono>       // std::chrono::system_clock

int main ()
  using std::chrono::system_clock;
  std::time_t tt = system_clock::to_time_t (system_clock::now());

  struct std::tm * ptm = std::localtime(&tt);
  std::cout << "Now (local time): " << std::put_time(ptm,"%c") << '\n';

  return 0;

Possible output:
Now (local time): 03/07/13 11:41:34

Data races

Accesses the object pointed by tmb and the array pointed by fmt.
Modifies the stream object where it is inserted.
Concurrent access to the same stream object may cause data races, except for the standard stream objects (cout, cerr, clog, wcout, wcerr and wclog) when these are synchronized with stdio (in this case, no data races are initiated, although no guarantees are given on the order in which characters from multiple threads are inserted).

Exception safety

Basic guarantee: if an exception is thrown, the object is in a valid state.
It throws an exception of member type failure if the resulting error state flag is not goodbit and member exceptions was set to throw for that state.
Any exception thrown by an internal operation is caught and handled by the function, setting badbit. If badbit was set on the last call to exceptions, the function rethrows the caught exception.

Note that invalid arguments cause undefined behavior.

See also