Nautiterm - "sun is over the yard arm"

Nautiterm: (Nautical Terms Explained) - Sun Is Over The Yard Arm - "Time for happy hour to begin”. This term is thought to have its origins in an officers' custom aboard ships sailing in the north Atlantic. 

In those latitudes and at around 11am; the sun would rise above the upper yards (the horizontal spars mounted on the masts), from which the square sails were hung. Since this coincided with the forenoon 'stand easy,' officers would take advantage of the break to go below for their first tot of spirits for the day.