Depends what I’m doing. On an average home office day I barely even wear socks outside of dropping the kids off at school, so the pair that ~I’m currently wearing~ is on the floor next to my bed has been used three days in a row.

When I’m doing field work it usually means long days of wearing shoes, often in hot climate, and often loafing around airports. For those days I always pack three extra pairs of clean socks to have in my kit.