Enable FIFO based on date stock is received

There is currently no FIFO option, which operates solely based on the date the stock is received. I spoke with support and they advised i must give the products an 'expiry date' when received in, and use that to rotate the stock (i.e. using FEFO, not FIFO). However, our products do not have an expiry date, so it looks as though im going to have to make them up. This will create more work than is necessary though. Mintsoft already records the date stock is received on the system - from this, I would have thought it should be reasonable easy to include a FIFO option, to ensure the system automatically allocates the stock which was received in the earliest? Please would you be able to help with this and build it in to the system, thank you!!