Once again, my dog closed my browser after I typed a nice long detailed message...let's try this again...
When I had a lot of reptiles, I had a dry erase board that I would use to write down everyone's feeding habits.
The one thing to keep in mind is, if you regularly feed your snake every seven days and then forget and miss a week, your snake will not starve. They aren't creatures of habit like birds, they're creatures of opportunity, in the wild they can go months without catching a single prey item, then go a week and have several meals. They are built to withstand periods without food. I'm sure it's much better on them health wise to have a regular feeding schedule, but I really doubt anyone has forgotten to feed a snake to the point that it actually suffered any or starved to death. You would almost have to intentionally not feed them to forget about them for that long. Of course I'm speaking about adults here and mainly ball pythons. There certainly are smaller species, like garter and ribbon snakes, that need to be fed quite frequently or they will quickly perish. Even a baby ball can go quite a few months without eating, like I said, I wouldn't recommend it but they will survive.
Years ago I bought a baby ball from a reptile show, when I got him home I realized that he was wild caught and not captive bred as the seller claimed. How I realized this? I found a couple very strange looking ticks on him that had been wedged in between his scales, I didn't notice them until I took him home and gave him a really good once over in decent lighting. The same snake refused to eat for six months, I tried everything in the book for trying to get a fresh import to eat and nothing worked. I was so upset, that was one of the many reasons I purposefully only bought captive bred animals. After about six months I finally got him to eat a mouse, I was sooo happy I thought things were looking up. The snake ended up dying a week later. I can only suspect that he had gone so long without food that he was too malnourished to digest the mouse he had finally eaten. Bear in mind, this was a very young snake and six months is an incredibly long time for a baby snake to not eat.
Anyway... now that we only have a few snakes, we just picked one day of the week, friday, to be snake feeding day. That way every friday we know the snakes need to eat. And having snakes that eat prekilled food is SOOO nice! Not only is it more humane for the mouse/rat but the freezing process also kills any parasites that can be commonly found on live rodents, it's also much safer for the snake, many snakes are very badly injured by live prey items. And the biggest plus, you can buy them in bulk and just keep them in your freezer. Then, whenever you need to feed them, you just pop out a mousesicle and let it thaw for a bit, then give it to the snake. No driving to the pet store every time you have to feed the snake, no dealing with stinky mice, getting bit by said mice, having to watch your snake eat a live mouse, and best of all, if the snake decides he doesn't want to eat, you can just toss the mouse out. If you feed live and your snake decides it doesn't want to eat, you're stuck taking care of what was meant to be food, and if you're like me, you'll get attached to said food and it will become yet another pet :20: