A clockmaker has old fashioned clocks in 3 colors. He winds his red clocks every 3 days. He winds his…

A clockmaker has old fashioned clocks in 3 colors. He winds his red clocks every 3 days. He winds his blue locks every 4 days. The green clocks are wound every 5 days. On which day will he wind the red, blue and green clocks on the same day?