This is according to an alleged leaked document from Vodafone Germany which shows the possible release date for the handset. We expect that sometimes carriers are given heads up as to when products might become available so that they can plan their marketing and get it ready for sale, but at the same time for all we know, Vodafone Germany could simply be speculating, so take it with a grain of salt for now.
That being said, we have heard how Sony plans on launching both the Xperia Z3 and Xperia Z3 Compact alongside one another. The Xperia Z3 Compact is essentially a smaller version of the Xperia Z3, but at the same time the leaked specs of both handsets suggest that they will share similar hardware specs, with the latter just being a smaller version.
For starters it seems that both the Xperia Z3 and the Xperia Z3 Compact will feature a Qualcomm Snapdragon 801 chipset clocked at 2.5GHz. However the Xperia Z3 will feature a Full HD display while the Xperia Z3 Compact will pack a HD display. It also appears that the software on both phones will be slightly different, with the Xperia Z3 Compact running on Android 4.4.2 KitKat while the Xperia Z3 will run on Android 4.4.4 KitKat.