Calendar

hi there guys !
I am experiancing a little problem and would love to get some help. on my new forum when I change the calendar to Sunday as the start of the week there is a problem with the dates, I creats a delay of 1 day later by the name of the day and the actually date number.
for example:
today is Friday 16th, and in my calendar it shows as the 16th is Saturday........

Is there a solution for it ?
Is is a bug ?
am I seeing it cause I use hebrew ??

my forum is on :
http://taldor.forumotion.com

looking forward to get an answer, the forum is very important to me. specially the calendar, and I cannot mistake people that visit my site..
thanx a lot guys and I really enjoy being a part of ur community !

Did you change the GTM ( Time ) on your forum yet?

yea thats the one, System Timezone in the general cofiguration, just needs setting to your local timezone