Restock times

Credit to Pinkdottedbow for this list.

0/5: batteries, cleaning products, computers, contact lenses, dvds, flowers, frozen food, male clothing, musical instruments, pots of paint, sunglasses, tools, vegetables

1/6: appliances, balloons, chocolates, coffee, costumes, egs, female clothing, minipet food, minipets, pearls, school supplies, seeds, sushi, weapons

2/7: armour, bakery, candy, charity, coffee, giant vegetables, gourmet meats, halloween treats, illegal concoctions, male shoes, pizza, soft drinks, wallpaper, wigs

3/8: books, canned food, car parts, fast food, fruits, furniture, giant flowers, hair dye, ice cream, potions, stars, voodoo dolls

4/9: cds, charms, cooking ingredients, female clothing, flooring, giant fruits, lipstick, magic, medicine, stamps, toys, trading cards

Obtained on marapets, source unknown...
Smuggler: He restocks at 14 minutes past the hour at any random hour