How do I prove that the contract was breached in February 2011 when the other party is stating that it was breached in 2010? Does the suit have to be filed in court before February ends or I can hire a lawyer and send the other individual a 21 day notice to comply?
You need to file suit as soon as possible to preserve your right to do so. Each of the parties will put on evidence of the date they claim the breach occurred. The Court will weigh that evidence and make its finding as to the date of breach.