some folks keep their parrots to match the daily cycle of light to dark ( sunset to sunrise) or keep their parrot toa strict 12 hour cycl. We keep Salty to the latter, and he has never given us any trouble in that regards.
I've always heard to consistently keep 10-12 hours as good. Because of my work hours, we've set Cairo on roughly 11pm to 11am. Most weekdays, he'll sleep in past noon - that's just when my partner, who freelances from home, is ready to engage/train him. On weekends, we typically wake him up around 9-10am, so we can go for a morning flight.
If we kept to local sunrise/sunset, being on the equator, he'd hardly get to see me with a 7-7 timing (I've a 40min commute with 9-6 work hours that often go into overtime). So now with the 11-11, at least I reach home just after 7pm (sometimes closer to 8pm) and have a few hours to feed, train, and play with him. We do go on walks at dusk as well - I try to make sure we can go on walks at least every other day, even if it is a bit dark outside.
It helps that we keep his sleep cage covered strictly at those hours. I just pop in a bowl of fresh food before I leave for work, which he eats whenever he wakes up and feels hungry. He'll sleep peacefully through normal talking (we have a Raspberry Pi setup with IR camera to check on him), so us humans can have our own separate sleep schedule.
When we were casual about his sleep, he was a bit grumpy, so I do feel much better about tucking him in on schedule. And he's good with a regular schedule - the moment we cover up his sleep cage and tell him, "night night," he does one last climb inside his cage before settling down to sleep.
Him being an ekkie, I'm not sure how much that factors into a difference with caiques.
I deal carefully with iight mainly as a management tool for hormones and molting.
Ever since the Rickeybird hit sexual maturity at about 3-4 years of age, I've had to manage his hormones! If kept on too steady a long day, and too much light, he stayed "in the mood" (aggressive, even louder than usual, pleasuring himself on my neck ) year round. If I keep him on a natural light schedule... up with dawn, down with dusk, year around... THEN he's only a little monster rooster from July to September). He has his own room, so I can do that easily.
And he has two regular molts a year... approximately January-February and July-August.
A crossover Quaker Scuti (F), A Sun conure named AC, A Cinnamon Green Cheek conure Kent, and 5 budgies, yellow (m), clark Jr. (m), Dot (f), Zebra(f), Machine (m).
Clark normally goes about 11 hours on his own, but he cuddle sits beside me sometimes so that might make up some difference. Or he just only needs 11 hours. .....Or he's insane (option 3 is always on the table)
Senegal Parrot named "Kane"; Yellow-Sided Green Cheek Conure named "Bowie"; Blue Quaker Parrot named "Lita Ford"; Cockatiel named "Duff"; 8 American/English Budgie Hybrids; Ringneck Dove named "Dylan"
Your bird is likely irritable due to their hormones being out of control...'Tis the season!
12-hours of sleep is the normally-recommended amount for a parrot, because that is roughly the amount they will get if you keep them on a "Natural Light Schedule", as Gail already spoke about and gave you great info about...
A "Natural Light Schedule" is the best way to keep your bird's hormones under control, and lessen those mood-swings and irritability. What is often forgotten or disregarded about a bird's sleep or even the "Natural Light Schedule" is that not only does the bird need to wake-up with the sunrise and go to sleep with the sunset, but they need to be able to SEE the light changes as well. Usually this is easily done as long as the cage they sleep in is located in a room with a window, and you don't cover their cage until after the sunset happens. Obviously if you follow a strict Natural-Light Schedule the time that they wake-up and the time that they go to sleep are going to change throughout the year depending on what time the sun rises and what time the sun sets, and it also depends on where in the world you live. However, the concept is always going to be the same, regardless of where you live, what time of year it is, etc. When the sun rises in the morning, the bird wakes-up (this usually happens naturally with most birds anyway every single day, as long as they can see the light change)...It's the "going to sleep just as or just after the sun-sets that is usually the problem and is not done naturally by the bird if they are with their people at night. Some people cannot put their birds to bed right at sunset, especially in the winter because it's so early, they'd never get to spend any time with their bird...It's much easier to follow in the summertime.
However, as long as you can ensure that your bird is getting at least 12-hours of "restful" sleep ever night, or more, then he should be well-rested and not be irritable due to a lack of sleep. Make sure that the cage or stand where he sleeps is in a room with a window and that the blinds/curtains are opened enough that the light changes in both the morning and at night are able to be observed by your bird. Think of how wild birds sleep and wake-up...If you think about it, you don't hear any birds outside after dark, except for the nocturnal ones like owls. If you're ever outside right around sunset sometime, take note of you hearing the wild birds outside, usually very loud right before sunset, and then as soon as the sun has set they are silent...And we all know that the birds outside start their "talking" as soon as the sun starts coming-up...
The other factor that can help your bird's hormone-levels in a natural way (meaning without using any medications to alter his hormones) is his regular, daily diet. If your bird's regular, daily diet is low in fat, high in protein, low in sodium, low in sugar, high in vitamins, minerals, and amino acids, and is varied, meaning he gets an abundance of different foods each day to stimulate him mentally as well as physically, this too has a great impact on his hormone-levels and his sleeping-pattern.
M & M are by two windows that let in tons of afternoon light, but less so eastern exposure. They sleep pretty quietly therefore from when we put them to bed (around 9-10) til 7:30 the next morning. That's the only half an hour of outside time they'd get til I get back from work between 3:30-4. They're on then for another hour or so, then in to eat and sleep til being roused against when B gets home.
My birds typically gets 10-12 hours of sleep, but I'm guessing if your bird is irritable due to hormones, it's best to get a bit more than 12 hours. We cover our birds' cages so it's dark enough and we try to keep noise to a minimum so they get enough sleep.