Conflict between TikZ and university thesis class file

Question

When compiling a document using my university's thesis class file and the TikZ package I receive an error message (missing number, treated as zero). Would someone know how I can solve this problem?

\documentclass[phd,bottom,nosig]{usbthesis}
\usepackage{tikz}
\begin{document}
Test 1-2-3
\end{document}

The class file can be found here:

http://graduate.physics.sunysb.edu/faq/thesis_template/usbthesis.cls

Answer 1

In usbthesis.cls change the line:

\renewcommand{\year}[1]{\newcommand{\@year}{#1}}

to,

\newcommand{\myyear}[1]{\newcommand{\@year}{#1}}

and use \myyear rather than \year in your document.

It looks like pgfmathfunctions.random.code.tex uses \year to generate a random seed. Since the class redefines \year before it's use in that file, you're getting the error.

Answer 2

The class file badly redefines \year, which is a TeX macro for the current year, and is used by pgf to set a random number seed when it loads.

Changing the order of loading the packages, as Peter Grill suggests, will fix the MWE but other issues may still be present.

In the following, use \setyear instead of \year from the class:

\let\oldyear\year
\documentclass[phd,bottom,nosig]{usbthesis}
\let\setyear\year
\let\year\oldyear
\errorcontextlines=\maxdimen
\usepackage{tikz}
\begin{document}
Test 1-2-3
\end{document}

You should probably also do something similar for \month.

If you are able to tell the University to fix their class file, then Scott H.'s answer is preferable (with a \mymonth as well).

Answer 3

If you don't want to change the .cls file you could simply add

\RequirePackage{tikz} 

before the \documentclass.

Code:

\RequirePackage{tikz}
\documentclass[phd,bottom,nosig]{usbthesis}
%\usepackage{tikz}% no longer needed.
\begin{document}
Test 1-2-3
\end{document}