30 Localization library [localization]

30.4 Standard locale categories [locale.categories]

30.4.6 The time category [category.time] Class template time_put [locale.time.put] Virtual functions [locale.time.put.virtuals]

iter_type do_put(iter_type s, ios_base&, char_type fill, const tm* t, char format, char modifier) const;
Effects: Formats the contents of the parameter t into characters placed on the output sequence s.
Formatting is controlled by the parameters format and modifier, interpreted identically as the format specifiers in the string argument to the standard library function strftime(), except that the sequence of characters produced for those specifiers that are described as depending on the C locale are instead implementation-defined.
[Note 1: 
Interpretation of the modifier argument is implementation-defined.
— end note]
Returns: An iterator pointing immediately after the last character produced.
[Note 2: 
The fill argument can be used in the implementation-defined formats or by derivations.
A space character is a reasonable default for this argument.
— end note]
Recommended practice: Interpretation of the modifier should follow POSIX conventions.
Implementations should refer to other standards such as POSIX for a specification of the character sequences produced for those specifiers described as depending on the C locale.