This is not true.Place egg in several inches of water. If it sinks to the bottom, it is good. If it floats, it is bad.
The eggs we get at our markets are "old" by the time we get them ... Shipping from you all (Mainland) is about a month, refrigerated. I'm with @rosemarythyme although eggs laid by my girls are gone by the end of the month I only have 4 girls so between Hubby & friends, they don't last long in the frig.