It is possable for someone to know the present past and future but not know ALL of it and thus not be omnicient.
POKEY IS A SLAAD. HELLO SMALL CHILD HE LIVES IN THE ANTARCTIC CIRCLE!!!
Who said hell can't freeze over?
— A traveling human cleric when he arrived in Cania's City of Lost Souls in Baator
It is possable for someone to know the present past and future but not know ALL of it and thus not be omnicient.