Google calendar.
I have my own diary on there, a family diary that is in a different colour and a meal plan in a third colour.
So everyone should know what's happening each day and what's for dinner (DH and DD are both good at getting on with the cooking if I'm not around, but the need telling what I've planned and shoppe for).
I find google calendar best because I can enter stuff years ahead (eg phone contract due for renewal, or mortgage agreement etc) and repeat items yearly eg birthdays - I enter the details once (including year of birth) with an annual repeat. That way I can easily work out if it's a 21st, 40th or whatever.
And it's easy to add calendar invites onto google calendar, such as PTA meetings etc.
Apart from calendars, I've got myself into quite a good laundry routine - Monday bedding, Tuesday light colours, weds darks, thurs towels, fri whites, sat light colour, sun dark colour. Ironing on Sunday.
Meal planning is a great time saver. I've got 31 meals/recipes in a folder. So we always have Bolognese on 1st (for instance). And as it's a 31 day rotation, we don't always end up having Bolognese on The same day of the week. If it's a birthday or we're out, I just skip that day. It makes it very easy to do my supermarket delivery order.
I always get my shopping delivered weds (cheap subscription) and the minute it's in the cupboards I book the next slot. I've generally got slots booked 3 or 4 weeks ahead.
I've jut realised this has turned into a preachy essay. So I'll leave it at that 😂