Parents Visiting

Hiya

I am a British Citizen living in the UK and I would like to bring my parents to visit. In Iran my Father doesnt tend to use his bank account for day to day spending, he is paid by his tenants in cash and uses that to live on. I wish for them to come UK for a 2 month holiday. My Father can provide translated documents of his house deeds and tenancy agreements that he has with tenants, but he has only started to pay regular sums of money into his bank account this month. It says on the UKBA website that six months of bank slips are required or a copy of a balance showing when the account was opened and then backed up by showng transaction history. I was hoping they would apply for their visa around June time and hopefully be succesful and come to the UK in August or september. will 4 months of bank statements suffice or will the full six months be necessary?

Many thanks