Unemployment base period?

I got a notice of determination and in section 3 it says the employer is not chargeable since the employment was not in the base period. I was hired June of 2010 and fired February 2011. I don't understand base period.|||you have to have worked for the employer for a certain length of time, which varies state to state, and earned a certain amount to qualify. you'll have to find out what your state's requirements are.