Question about not allowing items not in stock yet to be bought

I had asked this earlier in the week, but my post about it is way back on another page by now, and there was no satisfatory resolution to the issue anyway, so I thought I'd try again.

Here is what I would like to do and what actually happened:

I had a sale coming up on certain items that were not available until a certain date. I wanted the items to show up in the cart, but not be available for addition to the shopping cart until that date.

The only way I could do that was to make the items "out of stock", but with an expected date set.

This accomplished half of my goal. The items were still showing on the cart, but were not available for purchase, so far so good. Changing a few settings removed the "Sold Out" graphic and still did not allow the item to be added to the shopping cart. Even better, but......

The problem was...... On the sale date, I had to go in at midnight and change all of the "out of stock" items to "in stock" by adding the amount of inventory on hand to each item's page.

Is there a better way? Did I screw up? Do I need an add-on?
I don't want to have to do this again for the next sale......

You could alter the button function so that when the product is not yet available it shows a Coming soon ... button/image/link to something else vs the add to cart ... then it will automatically change at midnight with the proper stock that you added last week, month, etc.

This would save you a lot of time and problems to have this handy dandy feature added to your shop ...

So put on your coding hat ... :smartass:

Or, perhaps post a Commercial Help Wanted on this ... if coding is not your game ... :lamo:

Or, contact someone who might know how do write this nifty code to work in Zen Cart for you ... :cool: