To start at 9am you're often fighting school traffic, or public transport is rammed with others also wanting to get to work for 9am.
The traffic can cause distress, cramped conditions can cause distress, diversions or delays can cause distress.
I mentioned in an earlier post I had a train terminate at an earlier stop due to vandalism on the line. This is distressing enough as I do not have the capacity or executive functioning abilities to sequence or prioritise what steps to take next in order to reach the end goal, it causes confusion and panic to the point where the emotional and behavioral outbursts are out of my control. My brain also lacks the ability to filter out relevant sensory information, so whilst you might be able to hear and see everything around you and pick out which bits are necessary like hearing someone give instructions in a busy place or hear traffic coming on an already busy street, I can't filter the necessary bits out and my brain tries to process all of that sensory information all at once, leading to an overload of information.
So on this day in my previous example, I had got on a train to arrive at work for 9am, it was busy and crowded so I wore my headphones to drown out the noise of people.
Because I had my headphones on I couldn't hear the tannoy, suddenly at the next stop EVERYBODY stood up to get off the train. This isn't what usually happens. This immediately triggered panic, and I froze in fear. The conductor then came up to me and gestured to remove my headphones so I took them off. He said I needed to get off as the train had terminated here, and if I wasn't "acting cool and wearing those stupid headphones" then I would have heard the tannoy.
He immediately became an "unsafe" person to ask for help so this caused more panic and in my head flooded a list of things to do and things I was feeling like: get to work, get off the train, call my boss, I'm going to get sanctioned, which way do I go, how do I stop panicking, everybody is looking at me, where are they all going.
So I got off the train, and heeding the harsh words the conductor gave me, kept my headphones off. There were so many people all talking to one another but because there were so many voices I couldn't hear anything anyone was saying. I was trying to listen for a tannoy, but it felt impossible and distressing.
Someone tried to talk to me but I have no idea what they were trying to say to me and it just made me panic more.
I ended up running off pushing through the crowd and screaming help, I was eventually intercepted by police who did not understand what an autistic meltdown is or how it can present and they all talked about me to each other instead of to me. I was taken to an A&E in the hospital closest to that station that I had never been to before which again caused my anxiety to spike and behaviours to escalate and was offered some sort of sedative or anti-anxiety medication, under threat of being held involuntarily if I didn't comply. All I kept saying was "can you call my boss please and tell her I'm in the hospital?"
If this had happened an hour later, less people, less eyes on me, less general noise, I would still have been anxious but I would have had a better chance of getting help and finding my way without it escalating to a meltdown.
I might have needed time to adjust once I'd gotten to work, it might have meant I was less productive that day, and my pay was docked, I might even have needed to just go home and work the time back another day, but I wouldn't have gotten to the point of meltdown.
As it is if has left me terrified of public transport because it's already uncomfortable for me, but it's utterly unpredictable and public transport is just always going to be that way. I can't control that, but I can control the times that I use it, and use it to my advantage rather than disadvantage.
So I'm not OP, but I hope this has shed some light on why the 1 hour difference can help.
Not to mention in addition many of us autistic folk struggle with sleep due to sensory overload from the previous day as well as delayed sleep phase syndrome which means that we need to sleep in a bit later than others because we cannot get to sleep until later than others and when we're tired our sensory sensitivities are heightened, as well as our executive functioning abilities are decreased. These sleep issues can come in cycles, little stints, be permanent and some autistic people never have them but they are a comorbidity of autism and so a large portion of the autistic population will experience these issues at some point, to a higher degree than an average NT person.