Questions

I was always told Wednesdays for most.  but I think it really depends on when their shipments arrive as I have seen stocking on other days as well. 

The ship usually arrives on Sunday so by the time everything clears customs its Tuesday or Wednesday by the time the containers start rolling into the loading docks of the stores. 

@jaxstcroixcondo

The market in La Reine is on Wednesday and Saturday mornings.

There's also a nice market at the department of agriculture on Saturday mornings, but you need to get there early for the best selection (they open around 8).

Several of the 20' farm stands provided through the department of agriculture grants are open multiple days per week (locations and times vary).

Stores restock the shelves throughout the week, but I've not identified a consistent pattern, although I believe @vicanuck is right on the delivery patterns. If there's things I need that I can't find at my usual stores, I keep a list on my phone and a small cooler in the car and hit stores in other parts of the island when I'm there.

Grocery stores tend to be busier the first 2 days of the month (so I try to avoid them unless I really need something), but I've had pretty good luck finding fuller shelves the last 2 days of the month (when the stores are getting ready for the first of the month rush).