Sunday is a day of rest. For some people Sunday is just another day of the week. Some people take the day of rest to extreme. They say, it is not a day of play, unless play makes you restfull. It is not a day of work at home because you are not at work. These are the same people who say Sunday is for God.
It is difficult when you work all week and your only day off to do what needs to be done for your family is on Sunday. Does that make you a bad person? No. You are a human. Humans need clean clothes and food. If you use Sunday to take care of survival needs it is not work.
If you want to be a Sunday Christian, keep only the Sabbath holy and do whatever you want to the other days, do not waste your breath telling me how Sunday is for God.
Everyday is for God. Everyday should include time for prayer or soulfulness. Find a day of rest during your week and more importantly, invite God into all your days not just Sunday.