d =: (3000&$;._2) 1!:1 < 'day03' slop =: 3 : '+/''#''= d{~ y <@:*"_ 0 i.>.(#d)%{.y' slop 1 3 NB. 270 */ slop&> (1 1; 1 3; 1 5; 1 7; 2 1) NB. 2122848000