My mother used to often not cook a "proper" meal on Sundays!
However I cook several times a week and eat the same thing until it is gone, or else I freeze some and several months later, I throw it out!
But basically I guess I do not cook every day as I find I cannot cook for one person if I am eating alone as it is not worth it so I eat the same thing several days and this does not bother me.
I cook most weekdays. Every now and then I will go for the easy option and buy dinner for the family. However, my husband usually cooks on the weekends which gives me a break too. I really appreciate that because I'm not a huge fan of cooking.
Sunday is usually the day we have a large dinner as the older grandchildren compete almost every weekend in athletics and there is not enough time for my daughter to cook a nourishing meal spending so much of the day at the track. We make up for it by having lighter meals during the week like home made hamburgers, butter chicken and try to have 2 fish meals as alternates after a night of a more substantial meal.
I cook every evening, but we'll have vegetarian pasta or lentils on Saturday night, tin tuna meal on Sunday evening, with a chicken thigh meal, Mondays, pork Tuesdays, Salmon fillets Wednesdays, beef Thursdays & lamb chops on Fridays. On the afternoon we arrive home from holidays, (4/5 times a year) we'll just have baked beans on toast with bacon & an egg, & sometimes maple syrup on top! That is the 1 night I don't like cooking a proper meal!