Malayalam Calendar 2004 followed in Kerala is provided by the Deepika Newspaper. The 2004 year Malayalam calendar contains important festivals in Kerala and uses Malayalam language to mention Nakshatram and festival details. This Kerala calendar of 2004 of Deepika is not in pdf format but in jpeg format. But you can save the webpage or image format and use it.
You can try this to use the main calendar link. (in this select the 2004 calendar for viewing)