This paper describes a way of implementing a conceptual model for temporal
data on a commercial object database system. The implemented version is pro
vided as a class library. The library enables applications to handle tempor
al data. Any application can employ the library because it does not depend
on specific applications, Furthermore. we propose an enhanced version of Ti
me Index. The index efficiently processes event queries in particular. Thes
e queries search time intervals in which given events are all valid. We als
o investigate the effectiveness of the enhanced Time Index.