My iphone says you must change your passcode whitin 60 minutes?

I'm scared to change it cause it never asked me before

The password might be too common for IOS7 I would do it if I was you:-)

Found this elsewhere:
If you installed a network profile and you are no longer using that, remove it. Settings->General->Profile tap and Remove
If you are still using the network, the profile is required for your contiued use and the password updates are part of the policy.

It could be because of your email exchange server. I had the same thing minutes after I added 2 step verification to my Hotmail