add time to gregorian calendar?

hi,

does anyone know a way of adding minutes to a gregorian calendar so that if i add (for example) 10 minutes to 6.55 it will go to 7.05 (as opposed to 6.65?)

at the moment i have created a simple date format (HHmmss) and parsed it to an integer so it can be compared to other times.

thanks for any help

[329 byte] By [Jazz8146a] at [2007-11-27 1:07:12]