hi aarona, it really dosn't matter what calendar program your pda comes with as there are so many calendar programs available from places like pocketgear.com and handango. It is more important to choose an os that is well supported by software writers so that you can easily cusomise your pda to suit your needs. if the calendar is the most important thing then look at what programs are out there and choose your pda accordingly. most of the programs will give you a free trial. the calendar program I use is freeware. | 
colour coded calander 
Linear Mode
