Increasing hours: extra day PW or longer hours?

[Miljah]

I currently work 09:00-17:00, Mon, Tue, Weds as a front line HCP. We get half an hour's unpaid lunch break but no tea breaks.

The unit is open 07:00-20:00. Full timers work 3 long days to make up their 37.5 hours a week. They get one paid half hour break, one unpaid half hour break per shift. They also do night shifts, Saturdays and the occasional 9-5, Mo-Fr in their rotation.

Due to my DS's age, I could now consider upping my 19.5 hours a week. I am not in amazing health, due to back pain issues, and I am 56! (so I minimise MH, but I'm on my feet a lot and have to do some MH. I'm not a nurse, but not dissimilar).

So, given that I believe my boss would snap my hand off if I offered any additional hours, thus I can request some flexibility, should I:

Offer a fourth 09:00-17:00 day per week? (so 19.5hrs to 25hrs pw)

Change my three normal days to two longer ones, say 09:00-20:00 (19.5 to 21hrs) plus a 'bank' day of 09:00-17:00 day per week (19.5 to 28.5hrs), the advantage of this being I can say no to a bank day. I am aware, though, of some days where, at 5pm, I go 'sod this!' and am very glad to be walking out.

I have to be careful not to offer 07:00 starts because that might catapult me into Saturday shifts which are chaotic and underskilled (tho offer a 1.3x uplift in pay).

I wonder if I could offer them a trial period? I can't decide what to offer.

WWYD?

Anyone?

A colleague who has opted for the 2 proper long days, 0700-2000, (not together) says 'it's tiring' but good to get her 25 hours out the way for the week.

FTR, I can't get up early so wouldn't start til 0900!

And my maths is wrong. I work 22.5 hrs pw, now. Not 19.5.

Are there associated transport costs with going an extra day?
I work part-time and do 5 mornings a week. I'd rather do the same hours over 3 days but it doesn't really suit my employer. It means I do five commutes a week instead of three, so a lot more petrol and wear & tear on the car.

I do three long days (10.5h) and one short day (6h) to make up full-time hours. I've got two small children and I care for an elderly relative, so the extra day at home does come in handy for medical appointments/home admin jobs that can't be done at the weekend. I don't miss having to use annual leave for medical appointments like when I worked 5 days, or having to pop out of the office eg. to make a quick call to the bank or post a parcel. It also means I can do the school runs, take the DC to their after-school activities and eat dinner with them one day per week, which I'd miss if I was still working 7.5h plus a 1h commute each way. So I'd say the work/life balance is better for working fewer, longer days instead of more, shorter days.

Is it possible to just pick up the extra shifts as bank and not be committed? You could still pay pension on them.

Thanks everyone.