Gregorian jailbreak tweak is a newly developed tweak made by Ryan Petrich the well known developer and the guy behind many awesome jailbreak tweaks. Today this tweak is available on his own beta repo at Cydia store and it is a great compromise for those who wish to remain on jailbroken firmware, but want to experience some of the cool new features introduced with Apple’s recent iOS 7.1 release.
Once you install the package, which takes about a minute or two to process, you will be asked to reboot your device. Upon rebooting, you’ll find a brand new app on your Home screen called Gregorian. The app looks just like the stock Calendar app, and can be used to outright replace the stock Calendar app.
Using the Gregorian calendar app is very much the same as using the stock Calendar app, but there is one major difference between the two. Gregorian features the iOS 7.1-inspired event views, which are accessible by tapping the show events button to the left of the magnifying glass near the upper right-hand corner of the app.