The end of Winter Break varies by school district.  If you don't know another parent to ask, the best way to find out when your child's school goes back in session is to check the school or school district website.  Most have a calendar on their website.  You could also try calling in hopes the school has the date on their outgoing answering machine message.   As a last resort you might try driving by the school to see if the break dates are posted on a marquee somewhere.  

If you need help finding your school or school district's contact information check out Education.com's Find a School Resource (link below).

Hope this helps!

Kat