Here they are, the order is day-name-route-item. It also tells you where/when to find them in their house on Route 26.
Monday - Monica - Route 40 - Sharp Beak
Tuesday - Tuscany - Route 29 - TwistedSpoon
Wednesday - Wesley - Lake of Rage - Black Belt
Thursday - Arthur - Route 36 - Hard Stone
Friday - Frieda - Route 32 - Poison Barb
Saturday - Santos - Blackthorn City - Soft Sand
Sunday - Sunny - Route 37 - Magnet