Is it okay if I sometimes skip a day of feeding my hamster?

It's usually best to toss out old food so it doesn't rot or get moldy. If left for a couple days it's usually no problem, but left for a week or more it can often get contaminated by the surroundings even if you clean, or may get moldy, especially if you live in a hot or hot and/or humid location.

As for not feeding them for a day? It's usually fine to fast them for a day. Keep in mind that hamsters actually have storage pouches in their cheeks/throat, and will often hold small amounts of food in them. They will usually find a spot to store food, but sometimes will keep small things in there for a few hours if they don't want it stolen. Cute little pack rats. I had two growing up, one of them would store as much food as he could in his cheeks and would bury it under his wheel, but would often keep the rare treats we gave them in his pouch until he was done with them, spitting them out to nibble here and there and then putting them back. =)

Also keep in mind that just because they stash food doesn't mean you SHOULD fast them thinking they've got stuff hidden as they may have eaten it a bit at a time in just one day. They have a quick metabolism and those stashes are for emergencies, so a rare fast is ok, but fasting them often is not. They should always have access to fresh water and food, especially if they're the smart ones who don't over-eat.

Yes, I left my hamsters with food whenever I go on a vacation. Usually for a couple of days and they're still fine. I've been doing that for 3 years and they are fine with that as long as you keep their cage with food :)

if your hamster has a stash then its okay not to feed them for a day,seeds and food that is one day old isn't going to affect your hamster at all.Good luck!

I would feed him every day and fresh water.spot clean every other day you don't want old food in your hamsters cage.