That could mean spending the day doing nothing.
Or cleaning your house to make your space enjoyable to live in.
Or decluttering for the same reason.
Or giving your day to others by volunteering.
Or cooking for hours and hours to share a meal with friends and family.
Or putting some hours on the bike or taking a big hike.
Or playing video games with a few friends online.
Or just slowing down enough to notice the little things in your day.
We all recharge in different ways. Sundays are for recharging.