At the start of the miniseries, it is the year 1600.  This is the same as it is in the book.

In the book, we see the date early one when Blackthorne writes in his log.  He dates his entry April 21 1600.  In the miniseries, the first visual after the opening credits is of the Erasmus alone on the ocean.  The voiceover tells us that the ship, along with others, left Europe in the year 1598.  Somewhat later in the narration, before there is any dialog between the actors, we are told that it is nearly two years later.  This implies that it is the year 1600 in the film just as in the book.