As long as you have nuclease-free buffer (TE pH8) to keep the DNA in, it will be OK in the fridge for months. I keep all of mine in the freezer though, since I read a study showing that repeated freeze-thawing of DNA does not do any damage. 

Store DNA at 4°C short term, –20°C or –80°C long term.

Both previous answers are perfect. Nothing to add.

Freeze it for long survival

TE buffer or DNAse RNAse free water at -20