(this is my first comment)

clankill3r,

I copied the code:
float f = 20.24;
println(f-20);
into a sketch and got the same result.
when I changed the value of 'f' to 20.25 and then ran it, it printed 0.25;
when I changed the value to 20.23, the result was 0.22999954;

I think it has to do with the println() function rounding the number or something, because 5 rounds up?
Only it seams that everything that does not "round up" actually rounds down...
when i tried the same number with a double, there were more resulting characters so I think it has to do with the int vs double capacity...

basically processing is doing something weird which is a little beyond me but I thought I'd share my thoughts

if you want to get the present hour and minute, there is always the hour() and minute() functions

but if you want hour and minute constants, there is nothing wrong with storing them as two separate floats:
float h = 20;
float m = 24;
println(m);
this works fine, but without the decimal

what is it exactly that you are trying to achieve?

I hope this helped

For the cause of the problem see: http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems

Storing the hours and minutes as separate ints does seem like a more sensible approach; though depending on what you want to do the Calendar/Time classes may provide additional helpful methods to work with...