I think I'm going to go against the grain a little here.
I don't like young children, they bore the pants off me. However, I do love my children (before anyone stupidly asks why I had them). The best thing for any child is not to experience me at my most stressed, tired, snappy state. Not for us both to be bored with that extra day when I plop them in front of a screen so I can get things done.
I'm not sure why people think weekends are not actually days. I like me time, I don't go shopping as a family as I have a busy weekend. I get it out of the way first thing in the morning so Saturday is gym and extra curricular for ALL the family.
If I had an extra day, I'd gym, yoga, lunch, shop, errands and pick them up early, bake and cook with them (just like we do at the weekends), we'd be less busy and life would be grand. As for them experiencing shopping at 2.5 - really? Unless their of any use to me like at 6 or 7, they can sleep a little longer on a Saturday.
If you get pure joy from your kids, I commend you. I don't. And that's okay. For me personally we get more from each other now than we ever did then. Now is our time.