\documentclass[]{article}
\usepackage{amsmath,graphicx,supertabular,hyperref,tabularx,ifthen}
\title{TIP \#209: Add [clock milliseconds], and [clock microseconds]}
\date{July 12, 2004}
\author{Reinhard Max}
\urlstyle{sf}
\setlength{\parskip}{1ex}
\setlength{\parindent}{0pt}
\def\tipversion$#1${\texttt{\$#1\$}}
\def\tiplangle#1{\ensuremath{<}}
\def\tiprangle#1{\ensuremath{>}}
\def\tipbar#1{\ensuremath{|}}
\def\tipmail#1#2{\(\langle\){\small\expandafter\url{#1@#2}}\(\rangle\)}
\ifx\pdfoutput\undefined
\newcommand{\tipimage}[2]{\typeout{Make sure you download #1.eps}\ifthenelse{\lengthtest{0.8\textwidth>#2}\and\lengthtest{0pt<#2}}{\includegraphics{#1.eps}}{\includegraphics[width=0.8\textwidth]{#1.eps}}}
\newcommand{\tipxref}[1]{}
\newcommand{\tipxrefend}{}
\else
\newcommand{\tipimage}[2]{\typeout{Make sure you create #1.pdf}\ifthenelse{\lengthtest{0.8\textwidth>#2}\and\lengthtest{0pt<#2}}{\includegraphics{#1.pdf}}{\includegraphics[width=0.8\textwidth]{#1.pdf}}}
\pdfcatalog{/PageMode /UseOutlines}
\newcommand{\tipxref}[1]{\pdfannotlink attr {/C [0.5 0.5 1.0] /Border [0 0 1]} goto name {#1}}
\newcommand{\tipxrefend}{\pdfendlink}
\fi
\newenvironment{tipabstract}{\begin{abstract}}{\end{abstract}}
\begin{document}\maketitle
\begin{center}\begin{tabularx}{\linewidth}{|r@{: }X|}\hline
\textbf{TIP \#209}&\textbf{Add [clock milliseconds], and [clock microseconds]}\\\hline
Author&

Reinhard Max \tipmail{max}{tclers.tk}
\\
Created&Monday, \(\text{12}^{\text{th}}\) July 2004\\
Type&Project\\
Tcl Version&\(8.5\)\\
State&Final\\
Vote&Done\\
Version&\tipversion$Revision: 1.5 $\\
Keywords&clock, milliseconds, microseconds\\
Post History&\\
\hline\end{tabularx}\end{center}
\thispagestyle{empty}\pagestyle{empty}
\begin{tipabstract}

This TIP proposes to replace \textbf{clock clicks -milliseconds} by \textbf{clock milliseconds} and \textbf{clock clicks -microseconds} by \textbf{clock microseconds}.
\end{tipabstract}
\tableofcontents\setcounter{page}{0}\clearpage\pagestyle{plain}

\section{Proposed change}
\begin{enumerate}
\item{}
Rename the \textbf{clock clicks -microseconds} command as defined by \cite{tip124} to \textbf{clock microseconds}.
\setcounter{enumi}{1}
\item{}
Deprecate \textbf{clock clicks -milliseconds}, and make it's functionality as defined by \cite{tip124} available as \textbf{clock milliseconds}.
\end{enumerate}

\section{Rationale}

In the author's understanding, the whole purpose of the \textbf{clock clicks} name was to indicate that the returned value is neither absolute nor guaranteed to have the same unit on different platforms. With the changes of \cite{tip124} in place both cases are not true anymore. Therefore the commands to return absolute timestamps with millisecond and microsecond resolution should be on the same level as \textbf{clock seconds} rather than being switches to \textbf{clock clicks}.

The \textbf{-microseconds} option can be removed from \textbf{clock clicks} immediately, because it never has been part of an official Tcl release while \textbf{-milliseconds} has to be kept at least until the next major release for backwards compatibility.

\section{Reference Implementation}

A reference implementation has been added to the Tcl patch tracker at SourceForge, item \#991742 .

\section{Copyright}

This document has been placed in the public domain.

\section{Colophon}

\textit{TIP AutoGenerator --- written by Donal K. Fellows}
\begin{thebibliography}{TIP \#1}
\addcontentsline{toc}{section}{References}
\bibitem[TIP \#124]{tip124}
Mark Harrison,
Kevin Kenny,
\emph{High-Resolution Absolute Time Values From [clock]},
on-line at \url{http://purl.org/tcl/tip/124.html}
\end{thebibliography}
\end{document}
