Marapets Restock Hint

If you don't know by now each shop has a specific number to it. For example, http://www.marapets.com/shop.php?id=1 is the Paint Shop, and http://www.marapets.com/shop.php?id=2 is the Glowing Egg Shop, etc. Well, the restock times are as follows:

If the shop number ends in a 1 or a 6, the restock time is 0 and 5.

If the shop number ends in a 2 or a 7, the restock time is 1 and 6.

If the shop number ends in a 3 or a 8, the restock time is 2 and 7.

If the shop number ends in a 4 or a 9, the restock time is 3 and 8.

If the shop number ends in a 5 or a 0, the restock time is 4 and 9.

No brainer! Ian was quite clever in coming up with it, and I thought I was quite clever in figuring it out. I am sure others have figured it out too, but it was a fun little puzzle to solve!