At least in the context of network devices clock synchronization tends to refer to synchronous circuits where a constant time signal has to be maintained so that two devices can know the precise rate at which data is being transmitted and received. If the respective clocks of two devices are skewed then the integrity of the circuit will suffer. As such it's fairly typical for one device to derive its clock from a neighbor which, in turn, either works from an internal oscillator or an external source.
Time synchronization is generally referring to maintaining accurate time/data values on a number of devices. An example of this would be through the use of the Network Time Protocol (NTP) which allows for synchronization of time/date to global standards with at least a fair degree of precision. Keeping accurate time is incredibly important for logging/forensic purposes but also crucial for certain cryptographic and security processes (among other things).
So - you can think of clock synchronization as being akin to making sure the second hand on two clocks are ticking at the same rate while time synchronization is making sure that the absolute second, minute and hour hands of the two clocks keep reading the same. As such it's possible for two devices to have clock synchronization but be set to different times and, within some definition, two unsynchronized devices to have very closely synced time/dates (or calendars as they're sometimes known).
As an aside - it's possible to get high-resolution timing devices that can both act as an accurate source of time/date information as well as providing high-resolution reference clocking but these functions can also potentially be had independently.