When you never know what time it is, and your family thinks it's polite to show up early.
A word that may address the headline of your question is chronomania:
chronomania n (Greek khronos, time + Greek mania, obsession, madness; cf. megalomania, balletomania) - obsession with time and speed; inclination to utilize every moment and to submit one's life to a total time control.
punctual, adj. arriving or happening at the time agreed on
tardy, adj. 1. slow to do something; 2. arriving late