How long 120mg. well, the half-life of methadone can be up to 59-hours, so after 2 and half days you would still have 60mg's in your system. But this doesn't take into account multiple doses.
A third type of lock is a security lock. This lock is like a typical password, to prevent someone other than the owner from using the phone. If activated accidentally, the user manual or carrier customer service can usually tell you the default code.
When you set up iCloud Keychain, you can create an iCloud Security Code. It can be a 4-digit code similar to the passcode lock for your device, or you can have a more complex code automatically generated for you.