Messages like
SEVERE setjy Leap second table TAI_UTC seems out-of-date.
SEVERE setjy Until table is updated (see aips++ manager) times and coordinates
SEVERE setjy derived from UTC could be wrong by 1s or more.
on Linux installations of CASA indicate that the "geodetic" directory of your CASA installation needs to be updated.
Instructions for performing this update are in the Knowledgebase article How can I update the data repository copy of my CASA installation? It is advisable to install a cron job which performs the update regularly.
With the OSX distribution of CASA, the update should be done automatically at each startup.