Creates a newly allocated string representing the requested format.
The format strings understood by this function are a subset of the
strftime() format language as specified by C99. The %D, %U and %W
conversions are not supported, nor is the 'E' modifier. The GNU
extensions %k, %l, %s and %P are supported, however, as are the
'0', '_' and '-' modifiers.
In contrast to strftime(), this function always produces a UTF-8
string, regardless of the current locale. Note that the rendering of
many formats is locale-dependent and may not match the strftime()
output exactly.
Since 2.26
Creates a newly allocated string representing the requested format. The format strings understood by this function are a subset of the strftime() format language as specified by C99. The %D, %U and %W conversions are not supported, nor is the 'E' modifier. The GNU extensions %k, %l, %s and %P are supported, however, as are the '0', '_' and '-' modifiers. In contrast to strftime(), this function always produces a UTF-8 string, regardless of the current locale. Note that the rendering of many formats is locale-dependent and may not match the strftime() output exactly. Since 2.26