%
% This file demonstrates various date formats and tests which apply to them
% for output
%
\documentclass[a4paper]{article}
\usepackage{fontspec}
\usepackage[american]{babel}
\usepackage{csquotes}
\begin{filecontents}[force]{\jobname.bib}
@misc{date1,
  note      = {Years with implicit era},
  author    = {Author1},
  date      = {-0099-07-11/-0043-03-13}, % Negative date range
  origdate  = {-0477},                   % Negative date
  eventdate = {0477/0566},               % Forced CE era due to dateeraauto setting
  urldate   = {-0020/0100},              % Cross BCE/CE range
}
@misc{date2,
  note      = {Dates with circa and uncertain markers},
  author    = {Author2},
  date      = {1723%},        % year with ISO8601-2 approximate (circa) and uncertainty markers
  origdate  = {1934-02~},      % year and month with circa marker
  eventdate = {1976?},         % year with uncertainty marker
  urldate   = {1922~},         % year with ISO8601-2 approximate (circa) marker
}
@misc{date3,
  note      = {Date ranges},
  author    = {Author3},
  date      = {1934~/1936~},    % year range with circa markers
  origdate  = {1723~/..},       % open-ended year range with circa marker
  eventdate = {1976?/..},       % open-ended year range with uncertainty marker
  urldate   = {1976/..}         % open-ended year range with open marker
}
@misc{date4,
  note      = {Times},
  author    = {Author4},
  date      = {2004-04-25T14:34:00/2004-04-25T14:37:06},   % Date with time, floating timezone
  origdate  = {2004-04-25T14:34:00Z/2004-04-25T14:34:05Z}, % Date with time, UTC timezone
  eventdate = {2004-04-25T14:34:00+05:00/2004-04-25T15:34:00+05:00}, % Date with time, explicit timezone
  urldate   = {2004-04-25T14:34:00/2004-04-25T15:00:00},   % Datetime range
}
@misc{date5,
  note      = {Seasons},
  author    = {Author5},
  date      = {1723-21},          % year divisions (21=spring)
  origdate  = {1934-24~},         % uncertain year plus season
  eventdate = {1934-22/1934-23},  % range with seasons
}
@misc{date6,
  % uses the 'nodate' localisation string due to default \DeclareLabeldate setting
  note      = {Date from literal/localisation string},
  author    = {Author6},
}
@misc{date7,
  note      = {Unspecified dates can be used to do amusing things},
  author    = {Author7},
  date      = {19XX},         % unspecified year in century
  origdate  = {199X},         % unspecified year in decade
}
@misc{date8,
  note      = {Astronomical year era},
  author    = {Author8},
  date      = {0001},     % with dateera=astronomical, 1, otherwise 1 CE
  origdate  = {0000},     % with dateera=astronomical, 0, otherwise 1 BCE
  eventdate = {-0001},    % with dateera=astronomical, -1, otherwise 2 BCE
  urldate   = {-0379}     % with dateera=astronomical, -379, otherwise 380 BCE
}
@misc{date9,
  note        = {Automatic era setting},
  author      = {Author9},
  date        = {1066},
  origdate    = {0876},
  eventdate   = {0402},
  urldate     = {-0382}
}
@misc{date10,
  note      = {More Date ranges},
  author    = {Author10},
  date      = {1034/},          % unknown
  origdate  = {/1034},          % unknown
  eventdate = {../1034},        % open-start to year range
  urldate   = {../1034}         % open
}
\end{filecontents}
\usepackage[style=authoryear,%
            % dateabbrev=false,% when false, don't abbreviate months/year divisions
            % julian=true,% convert dates before gregorianstart to Julian Calendar
            % gregorianstart=1582-10-15,% Default
            alldates=short,%
            % alldates=ymd,% Year-Month-Day format
            % alldates=iso,% ISO8601 format
            alldatesusetime=true, % print time components in non-compact date ranges
            alltimes=12h,%
            % alltimes=24h,% prints 24 hour format times (default)
            % alltimes=24hcomp,% prints 24 hour compressed format times
            % seconds=true,% uncomment to print seconds
            % timezones=true,% uncomment to print timezones
            datezeros=false,% pad date components with zeros?
            dateera=secular,% prints BCE/CE controlled by dateerauto, datezeros
            % dateera=christian,% prints BC/AD controlled by dateerauto, datezeros
            % dateera=astronomical,% prints astronomical dates, controlled by datezeros
            dateeraauto=600,% Sets the max year ceiling for automatic printing of era
            % abbreviate=false,% prints full date localisation strings
            dateuncertain=true,%
            datecirca=true,%
            sorting=none,%
            backend=biber]{biblatex}
\addbibresource{\jobname.bib}

\defbibenvironment{simple}
{\list{}
   {\setlength{\leftmargin}{0pt}%
    \setlength{\itemindent}{0pt}%
    \setlength{\bibitemsep}{1ex}%
    \setlength{\itemsep}{\bibitemsep}%
    \setlength{\parsep}{\bibparsep}}}
{\endlist}
{\item}

\DeclareFieldFormat{urldate}{#1}
\DeclareFieldFormat{time}{\mkbibemph{#1}}
\DeclareFieldFormat{labeltime}{\mkbibemph{#1}}
\DeclareFieldFormat{origtime}{\mkbibemph{#1}}
\DeclareFieldFormat{eventtime}{\mkbibemph{#1}}
\DeclareFieldFormat{urltime}{\mkbibemph{#1}}

\makeatletter

\DeclareBibliographyDriver{misc}{%
  \printfield[emph]{note}\\
  \iffieldundef{labelyear}{}{%
    \printtext[bold]{labeldate = }\printlabeldate
    \iffieldundef{labelhour}{}
      {\\\printtext[bold]{labeltime = }\printlabeltime}}\\%
  \iffieldundef{year}{}{%
    \iffieldequalstr{dateunspecified}{yearincentury}
      {\printtext[bold]{date = }\number\numexpr\thefield{year}/100+1\relax th Century}
      {\printtext[bold]{date = }\printdate
       \iffieldundef{hour}{}
         {\\\printtext[bold]{time = }\printtime}}}\\%
  \iffieldundef{origyear}{}{%
    \iffieldequalstr{origdateunspecified}{yearindecade}
      {\printtext[bold]{date = }The \expandafter\@gobbletwo\number\thefield{origyear}s}
      {\printtext[bold]{origdate = }\printorigdate
       \iffieldundef{orighour}{}
         {\\\printtext[bold]{origtime = }\printorigtime}}}\\%
  \iffieldundef{eventyear}{}{%
    \printtext[bold]{eventdate = }\printeventdate
    \iffieldundef{eventhour}{}
      {\\\printtext[bold]{eventtime = }\printeventtime}}\\%
  \iffieldundef{urlyear}{}{%
    \printtext[bold]{urldate = }\printurldate
    \iffieldundef{urlhour}{}
      {\\\printtext[bold]{urltime = }\printurltime}}%
  }

\begin{document}
\section*{Date formats}
This example file parses and formats some of the supported date formats and
demonstrates the output options. See the source for details. You can change
the options in the source file and this document will show you the options chosen.
\subsection*{Options used to format this test document}
\begingroup
datecirca=\textbf{\iftoggle{blx@datecirca}{1}{0}}\\
dateuncertain=\textbf{\iftoggle{blx@dateuncertain}{1}{0}}\\
dateera=\textbf{\blx@dateera}\\
dateerauto=\textbf{\blx@dateeraauto}\\
datezeros=\textbf{\iftoggle{blx@datezeros}{1}{0}}\\
timezeros=\textbf{\iftoggle{blx@timezeros}{1}{0}}\\
timezones=\textbf{\iftoggle{blx@timezones}{1}{0}}\\
seconds=\textbf{\iftoggle{blx@seconds}{1}{0}}\\
julian=\textbf{\iftoggle{blx@julian}{1}{0}}\\
gregorianstart=\textbf{\blx@gregorianstart}\\
\def\do#1{%
  #1=\textbf{\csuse{blx@dateformat@#1}}\\}
\do{labeldate}
\abx@dodates
\def\do#1{%
  #1time=\textbf{\csuse{blx@timeformat@#1time}}\\
  #1dateusetime=\textbf{\iftoggle{blx@#1dateusetime}{1}{0}}\\}
\do{label}
\abx@dodatetypes
\endgroup
\subsection*{Example Citation Formats}
\textcite{date1,date2,date3,date4,date5,date6,date7,date8,date9,date10}\\[1ex]
\cite{date1}\\
\cite{date2}\\
\cite{date3}\\
\cite{date4}\\
\cite{date5}\\
\cite{date6}\\
\cite{date7}\\
\cite{date8}\\
\cite{date9}\\
\cite{date10}
\printbibliography[env=simple,title={Example Bibliography Formats}]
\end{document}