Firstly, this is my first post, so if I break some etiquettes, please explain politely and I will try to learn.
Second, there were only three categories, so I picked "I hate this..." even though really is a small mistake that would be nice if it worked. It is not even close to arousing a sentiment like hate. In fact, I was shocked to see that there was provision for Hijri already built in. I didn't expect even that much, so I love it.
Finally, here is what I believe is a mistake:
Hijri is a lunar calendar, and cycles after about 354 days, not 365. When you go the the anniversary calendar view month for hijri, what you get is a hijri month, for example the 10th Safar 1431 corresponds to 26 Jan 2010. But in the box of 10 Safar you will get a list of all the events that occurred on 26 Jan in any year, not the events that occurred on 10th of Safar in any year.
For example, 10 Safar 1430 occurred on Jan 24 2009. I would think that in the Hijri view, each event should first be converted to hijri, and then those events that occurred on 10 Safar should be binned together. As it is, the binning is done at the start, based on the Julian date, and then the calendar is created later. This appears to me to be a mistake.