libeventdb question (list events)

Hello,

I am currently struggeling a small issue concerning libeventdb. As for
syncing I need to report every event that is in the database.
Unfortunately there is only a function "event_db_list_for_period" in
the libeventdb which takes two time_t as arguments to list all the
events between them. However I can't figure out is the maximum or
minimum value for time_t so that the code stays portable.

Or is there somewhere already a function that lists all the events?

Cheers,
Martin