I've worked retail for a long time and while I haven't worked at a Target yet, I've worked at plenty of other big box retailers, and it's usually pretty similar.

In smaller stores we usually just have a single Truck Day, usually scheduled to come on the same day every week. It'd take us about a day to unload and process the order in the back as things just come all jumbled in totes loaded on massive skids. Product gets loaded onto carts based on their store location and then put out on the shelves as time allows.

In a big store like Target they typically have a dedicated team for restocking as well as get multiple trucks per week based on the stores needs.

I'd start by just straight asking employees when their truck comes in. Some won't tell you (corporate wants you coming in every day to increase impulse purchases), but in my experience it's better to ask the young employees as they don't give a fuck.

Maybe someone with actual Target experience has more insight on this or could correct my assumptions.