To reduce from three days at work to two when my eldest starts school?

Drop the hours. Both me and my husband did. We aren't really saving much now and we don't get to go on really exciting holidays but it's not worth mugging yourself off for the sake of a fortnight in a hotel and a nicer car!
Just make sure you work enough hours to get the free childcare hours, make sure you can cover your mortgage and a proper pension, and make sure you'll have enough on the bank for if your boiler goes or your car needs a new engine and crack on.
Oh and buy a tent, you'll need it for the staycations!!!

2 days over 3 sounds like a good plan.

I did 2 full days - it was difficult! They were really long days and I never got it all done in that time so it carried over to the rest of the week. I also felt really disconnected to work. Wouldn't do it again if I could avoid it.

If you want to do it then do it, it doesn’t matter what other people are doing/think.

Having more time with your kids once they start school & their time with you is limited, being able to drop them off/pick them up (& not being completely stressed doing it!), & not sticking them in after school clubs after an already long day are all good reasons.

Have you thought about working every day but less hours? I do nearly school hours so drop off (breakfast club) and pick up (normal time). I need to work though so it was better financially to do 6 hours a day than drop a day or two a week. It requires some organisation but its nice not working past 2.30pm any day of the week. And its nice having the same hours every day to be able to do drop off and collections.

Other thing you’ve mentioned is this school. If you are going to a school a drive away as it’s marginally better in league tables etc have a good think. There’s a lot to be said for local school no long school run. It’s only 20 mins by car etc doesn’t factor in sheer grind of getting in car, traffic, parking hassle every day.

What are your school hol care plans? A shorter day can make accessing affordable holiday clubs easier as often they are 9-3 sort.

Why can't your husband work partially flexibly or drop hours to also accommodate school run?

Is he doing some of the childcare drop offs and pick ups? If not why not. One parent always having to be one with eye on clock and rushing around is a lot of pressure and often builds resentment.
A set up where one drops and one collects or shared is often best.

Do what works for you best , we are only here once .

concentrate on what will work for reception year…..worry about the rest later

It’s not indulgent at all. If you have decided that it will work better for you, then go for it. And actually doesn’t actually matter what anyone else thinks.

Missed that - yes, I can see that working well. I also worked 5 short days for a period when they were young teens and it worked well for me though many people would prefer to do less but longer days. It's all a compromise though, isn't it - I think when they are young you just feel you are slightly failing at parenting and work, but I'm glad I muddled through with various part time options. I got a fair amount of time with my kids and built a reasonable but not stellar career and pension - I wouldn't do it differently, though those years where you literally have no time for yourself at all are so tough.

surely it just boils down to affordability. Only you and DH can answer this.

And how did DH take on a fair share of this awful year? Or is his commute too long, job too busy...

It sounds like OP is still planning on working 3 days a week, just 0.4 FTE spread over 3? Is that right OP?

I'm on side with the whole "Why struggle if you don't have to" perspective, but it is also worth thinking critically about this from a long-term perspective.

Not just impact on your career, but what does it also mean for your pension or national insurance contributions? Could you end up in a much worse financial position than your husband jn your sixties or have to continue working longer than you would like to? Especially if you are going to do this over the next 7 to 10 years? The realities of the Gender Pension Gap are scary.

I would do some forecasting on the sums. It might make more sense in the long term to get a childminder for the extra couple of hours you need.

Any chance of DH picking up the slack? Otherwise you are facing into a long haul of being default parent for everything. School holidays, illness etc. You do you but it does let him proceed unimpeded!

My concern would be, you're doing this with your oldest starting school, so unless something changes you're looking at a long period (10+ years?) of your salary (and pension) being very low and your prospects for increasing that slim to none, which leaves you in a pretty vulnerable position financially if anything shifts in your relationship. What's the long term plan for your financial security?

Just a word of warning, I've done a 2 day/3 day alternate week job share pattern when my kids were small, and gone down from a 3 day to a 2 day week as part of transition to retirement. Both times, I found working 2 days was surprisingly difficult. By the time I'd got properly into the week, it was nearly over. 5 days home and 2 days work felt a bit unbalanced while 4 days home and 3 days work felt like it worked well.

However, those were both very demanding jobs with a lot of variety. In a routine job which is less varied, it might work perfectly well.

Just do it. If your DH isn’t keen it would be worth asking if he can find any flexibility in his schedule so he can do some of the running around.

Just do it. It’s not indulgent. Well it is if you’re planning Pilates, cocktails and taking a lover in the afternoon. But as a mother to two young children I’d imagine you’d be using the extra time to keep on top of the usual mundane shit. Definitely do it.