My Iphone keeps shutting down?

Chris Xu Asked: My Iphone keeps shutting down?

ok.. this has been happening for a while now… first my iphone shuts itself down even if it still has battery, then my parents suggested to charge the battery, i told them that the battery was full but, anyways, i did what they told me to see if it worked, it did work, it went like this: first the apple logo appeared, then it said "activation required" so i unplugged the cable to connect it to my mac so i can "activate it" but then the iphone shuts itself down again! and the dates are messed up! first it says its 6AM but then it turns into 8PM 1st of January?? and the thing just randomly changes (e.g. apple logo to "activate" thing and then to apple logo again) without even touching it and then it goes off again!
whats wrong with my iphoneee???