Software advice please?

I am looking for some advice on software for my mac please.
I work as a consultant and have lots of projects running at once. I want some software that we allow me to plot and plan my own time against projects and their deadlines.
Does anyone have any recommendations please? Happy to buy software or look at free software if it's right.

Thanks in advance.

A quick search at Macupdate gives this: Search for "time management" : MacUpdate