I’m so happy to hear that lots of other people don’t stick to a routine. This is one of the many pony club horse management rules that I break. My horses are generally safe and happy, but I sometimes joke about all the pony club rules I break every day
Yes, sometimes mine try to guilt me into feeding them something, anything, just because i went to the barn. I did teach them to come in when I whistle (which is a different whistle from calling the cats), and since I need them in stalls for whatever reason when I DO call them - feeding, blanket change, vet appt, whatever), I always put some sort of treat in their buckets. I don’t do that just because they went “hey, she’s there, maybe she’ll feed us!” LOL Just when I asked them to come down.
That’s one thing I’ve always liked about being in “mixed” (race horses and riding horses where schedules varied widely) or self-care barns. Nobody gets bent out of shape if someone else gets fed because they tag their being fed time onto their human is at the barn time rather than tagging their neighbour getting fed meaning they too will get fed shortly.
Also - forage always available makes a huge difference. I mean extra delicious snacks are always nice, but when they’ve got a full belly, they really don’t care much.
My horses prefer knowing when I am coming and are waiting for me at feeding time since I am very schedule oriented ( always have been) where animal feeding is concerned.
I think since your horses have 24/7 hay that feeding grain within a 2 hour window will make no difference and the risk of colic because of it is 0.
I do believe that your horse who is a harder keeper and getting a decent amount of grain would benefit from getting those 2 meals spread out 10-12 hours apart 7am-5-6pm as an example but that would be my preference.
In the warmer and longer daylight hours my horses are fed 7am, 6pm. During the Winter we feed at 7am 4-4:30pm so we can get things done in daylight. They adjust quickly.
I feed before work and after work. Time vary fairly widely if I need to drive in the office they eat and get turned out around 5:30 AM. A normal morning is between 6:30 AM and 8:30ish.
Dinner is similar. 2-3 hour range.
I’d love to do 24/7 turnout but it’s been so wet here, I hose off legs and stick in stalls to get them some dry time.
Knock on wood but no issues so far.
I have that 24/7 relaxed turnout, and one horse who’s been here 10 years and is now 30 colics like clockwork when there’s a big change in weather (barometric pressure, not necessarily temp).
My equines stalk the house. As soon as the kitchen light is turned on in the morning they are staring at the house at the fence closest to the window.

My equines stalk the house
Every once in a while I contemplate how nice it would be to live on the same property as my horse.
Then I contemplate the extra expenses of fluffy pink slippers and bathrobes in horse size, wear and tear on the furniture, my phone bill (she’s a talker), the constant need to have every room stocked with bonbons, and the constant breathing down my neck and harping about “You’re late. Again. Have you even started cooking my dinner yet? What’s in the fridge? OMG, how do you eat this stuff? Have you even read this label? There’s no alfalfa in this crap, not even any sugar. Absolute garbage! Why do you have the fruit drawer locked again? I don’t eat that much. Also, I’m letting you know that the candy bowl in the living room is empty and the clicker for the teevee is broken again, looks like someone stepped on it with a giant foot. Be a dear and grab me a pear from the LOCKED crisper would you? I’m about to miss the start of the afternoon soaps. Also, you had better get back to your desk. You’re the sole breadwinner in the household so you’d better get at it.”
Because she would find a way into my house and settle herself down to rule my entire life instead of just the few hours each day when I’m at the barn.

routine… the horses listen for the commuter train whistle in the morning, noon is the church bell, evening is the setting sun
So evening feed is at a different time every day?
My gelding only gets fed when I go to the barn., usually 6 days/wk. He’s boarded, out 24/7 with free choice hay and pasture.
He doesn’t eat much, enough soaked beet pulp to mix his powdered supplements in and pelleted vit/min. On the weekends it’s usually morning, weekdays in the winter it will be around 9pm, weekdays in the summer around 6pm.
No strict routine here either. I think the key is forage 24/7, pasture access to mill around and not being stalled. My horses are never upset. Yes, glad to see me for their special kibble but not stressed.
Wow, that sounds stressful. What is your routine for addressing the colic?
The first few times we called the vet, but now we just give him a dose of banamine. That has done the trick. If it was something catastrophic the banamine wouldn’t work, or wouldn’t work for long, but he goes back to normal pretty quickly.
That is awful and must be so stressful. I’m sorry you and your gelding have to deal with that.
Echoing above: there is routine, and then there’s routine. A happy herd with all their needs met and plenty of food is less concerned with “routine” than a barnful of horses standing in stalls with nothing to eat, fretting for their meal and escape.
Also, sometimes I think vets, being humans, put a little too much emphasis on the routine. Humans want an explanation of why something happened. It’a very easy to latch on to a change in routine as a plausible cause.
My horses have mostly had a similar life to what you describe, OP, with 24/7 turnout and a loose schedule. I remember once my mare had a melodramatic gas colic after dinner. I called the vet’s office and the on call vet, whom I didn’t know, came out. He was sure the colic happened because she got her cup of ration balancer a little later than usual and I was just a dumb owner who didn’t know she fed her horse late. Like he was putting words in my mouth: “you didn’t realize you were a little later with her dinner.” Uh, no.
I think if the horses have access to hay or pasture most of the time, routine isn’t such a big deal, especially since many horses on a forage first diet these days are getting bucket feed that’s pretty bland.
My mare and project mare get hay from a combination of electric drops and hand feeding. Sometimes the drops fail or I am late. I can’t remember the exact scenario but I do remember project mare missed a feeding and then got a lot of hay at once, and after an hour of gorging was lying down looking uncomfortable. Banamine handwalk and ok. After that I tweaked her feed drops and started using a hay net sometimes so she doesn’t have big gaps. Same thing happened once at the training barn, I assume there was a gap in her feeding.
Main mare gave herself impaction colic from not drinking heated bucket plus eating stemmy alfalfa. I took her off alfalfa and mothballed the heated bucket and hung a second water bucket right where her hay drops so it’s convenient to drink.
So you need to know why they are getting colic and what type it is. Main mare can skip meals, gorge and not colic.
They get small beet pulp and alfalfa cube mashes to carry supplements, some point in the evening. They know it’s after I’ve ridden or worked them and done their stalls so they aren’t frantic about mash when I arrive.
As others uave said no routine so you don’t get in trouble for being a minute late.
This works for the horses.
… but not next door’s guinea fowl!
I’m very strict on routine for my stable yard, but I was trained from a young age to be that way. It was “horses first before self” and that’s how I run my yard to this day.
Certainly, there are other appropriate approaches to horse care that work for both the horses and their humans, and I am not indicating that a strict routine is the only way to go, nor offering any criticism for those who have a more relaxed way of horse care than I do, but the old lessons die hard with me, and I’ve been able to make a strict schedule work all these years.
OP your horses are already on a routine- it’s a non-routine but it’s a routine they are used to:)
Long as they continue to have 24/7 access to hay, they are all drinking enough water, and they have blankets for these extreme colds we are starting to experience, they should all continue to be good:)
My horses have never been on a strict feeding schedule because I was working a lot and raising a child years ago. They were/are always on turnout with plenty of pasture or hay and get their feed pan stuffs within a two hour window most of the time.
Agree with whomever said not drinking enough water can bring on colic in either weather extreme - cold or hot. I try to watch each horse pee a few times a week as the color and the depth of color of the pee indicates if they are ingesting enough water:)
My remaining two are 27 & coming 29. 19 years ago, we retired to southern Middle Tennessee to get away from frigid weather. Boy was I glad to have medium weight blankets on hand when my area recently woke up one morning to a windchill of 20 below zero (F). They stayed plenty warm and I added a bit of non-iodized table salt to their feed pans to encourage drinking, which they have heated water tubs.
Just getting old can change how their digestive systems work or exacerbate an already existing issue - the seniors and elders need watched extra close regardless of weather:)

My equines stalk the house. As soon as the kitchen light is turned on in the morning they are staring at the house at the fence closest to the window.
That is what mine do! My gelding is in the exact same spot 99% of the time each morning and that gives him a perfect view of the back door.