This one is called Quarterly Calender, though I modified it heavily from the original.
It will show the current month in the center plus the months before and after, highlighting the current day.
Due to the difference in BGCOLOR support between Netscape and MSIE, I have code in this script to use nested tables with Netscape but not with MSIE. MSIE will color the space between cells if you put BGCOLOR in the TABLE tag, where Netscape will only apply BGCOLORS to cells.
You are free to use and modify this script, though it would be nice if you'd let me know.