I think they are important, it's how he told us to mark time.  I don't think the Jewish calendar is 100% correct in it's date though.  I think the luni/solar calendar is more close to how we were told in the Bible.

 

http://www.worldslastchance.com/lunisolarcalendar/web/WlcWeb.html

 

videos on the site explain thoroughly, according to the calendar we are just now in the 7th month.

kari