Exodus 20:8-10 "Remember that thou keep holy the sabbath day. Six days shalt thou labour, and shalt do all thy works. But on the seventh day is the sabbath of the Lord thy God: thou shalt do no work on it, thou nor thy son, nor thy daughter, nor thy manservant, nor thy maidservant, nor thy beast, nor the stranger that is within thy gates."

St. John Vianney (the Cure d'Ars) "Sunday is the property of our good God; it is His own day, the Lord's day. He made all the days of the week: He might have kept them all; He has given you six, and has reserved only the seventh for Himself. What right have you to meddle with what does not belong to you? You know very well that stolen goods never bring any profit. Nor will the day that you steal from Our Lord profit you either. I know two very certain ways of becoming poor: they are working on Sunday and taking other people's property."

 
"Sabbath" (or "Shabbat") means "cessation," "rest," not "Saturday," so the accusations against Catholics concerning not fulfilling God's Old Testament Commandment  to "keep Sabbath" are very moot. However, we are neither Old Testament Israelites nor practitioners of the post-Temple religion known as "Judaism," so we don't keep Friday Nights/Saturday days holy for their own sake, and we don't keep kosher, and we don't worry about carrying pencils or turning off light switches on the "Sabbath." We are not under the Mosaic Law (and Israel has never been under rabbinic law), but we are Israel, bound to obey the two great commandments -- to love God with all our heart, mind, soul and strength, and to love our neighbors as ourselves -- said two great commandments simply being more explicit in the Ten Commandments, which we are bound to -- not because they were given to Moses, but because they are the eternal laws of God, written into the hearts of men. The Sabbath ¹, as in "day of rest," therefore, we do keep; like the Apostles, we keep it on Sundays, as "the Lord's Day," because it was on a Sunday that Jesus Christ walked out of His Tomb and proved that He fulfilled the Law.

God created the world in six days, and then "saw all the things that He had made, and they were very good." Then, "on the seventh day God ended His work which He had made: and He rested on the seventh day from all His work which He had done." As He rested on that 7th day, He commanded Israel to rest with Him.

But He had that one, final work to do through His Son, Jesus Christ, a work predicted by the Prophets. This work was completed on the Cross ("It is consummated," John 19:30), and now the Sacrifice that allows the redemption of His now-fallen creation is commemorated and re-presented at the Mass. On Sunday, our priests offer the unbloody Sacrifice, the re-presentation of that same once and for all Sacrifice that led to that glorious Resurrection and, through which, if we accept, we may experience our own victory over the tomb. The Old Testament Sabbath was but a shadow of the Lord's Day to come.

Keeping the Lord's Day holy means, above all, going to Mass in order to fulfill our "Sunday duty" by participating in that Sacrifice. The sick, those who must care for the sick, women who've given birth in the past 6 weeks, and children under the age of reason (the age of 7), are not obliged if their presence would cause undue hardship, but all should do their best to attend, whether 6 months or 106 years of age (see Missing Mass, & Spiritual Communion)

In addition to attending Mass, we are to focus the day on God and His gifts to us by refraining from "servile work," that is, work that is necessary for a living. This is opposed to "liberal work" -- work that is recreational, relaxing, of performed out of charity for others. Some types of work might fall into either category, e.g., working on an old car might be work for a mechanic, but sheer joy for the car buff; cooking might be drudgery for the short order cook, but bliss for the woman who truly loves to cook. There is, then, some subjectivity here, but all Catholics must do their best to refrain from work that is servile, and arrange with their employers as much as possible to have Sundays free.

By the same token, Catholics should refrain from putting others in the position of performing servile work on Sundays, too. Don't put others in the position of breaking God's commandments. Note that some professions require work on Sundays, such as some aspects of medicine, law enforcement, firefighting, etc. -- work that is necessary or which serves charity. This is always allowable on the Lord's Day, as charity is always the highest law and the very purpose of law:

Matthew 12:1-15
At that time Jesus went through the corn on the sabbath: and his disciples being hungry, began to pluck the ears, and to eat. And the Pharisees seeing them, said to Him: Behold Thy disciples do that which is not lawful to do on the sabbath days. But He said to them: Have you not read what David did when he was hungry, and they that were with him: How he entered into the house of God, and did eat the loaves of proposition, which it was not lawful for him to eat, nor for them that were with him, but for the priests only? Or have ye not read in the law, that on the sabbath days the priests in the temple break the sabbath, and are without blame? But I tell you that there is here a greater than the temple. And if you knew what this meaneth: I will have mercy, and not sacrifice: you would never have condemned the innocent. For the Son of man is Lord even of the sabbath.

And when He has passed from thence, He came into their synagogues. And behold there was a man who had a withered hand, and they asked Him, saying: Is it lawful to heal on the sabbath days? that they might accuse Him. But He said to them: What man shall there be among you, that hath one sheep: and if the same fall into a pit on the sabbath day, will he not take hold on it and lift it up? How much better is a man than a sheep? Therefore it is lawful to do a good deed on the sabbath days. Then He saith to the man: Stretch forth thy hand; and he stretched it forth, and it was restored to health even as the other. And the Pharisees going out made a consultation against Him, how they might destroy Him. But Jesus knowing it, retired from thence: and many followed Him, and He healed them all.

In the spirit of the above and through tradition, in addition to emergency work such as firefighting and policing on Sundays, it is generally licit to work for restaurants, hotels, gas stations, museums, sporting events, and parks, and it's OK to visit such places on Sundays.

Sundays should be stress-free, relaxing, and conducive to thanksgiving, to looking at God's truly completed work with a "Deo gratias" in our hearts while strengthened, by the Sacrament we receive at Mass, to pick up our own cross.

To keep Sundays holy, we should prepare for them -- taking the trash out on Saturday instead of Sunday, throwing together meals on Saturday that can be warmed-up or baked off on Sunday, ensuring that children have their homework and chores out of the way, having the house clean, etc. We prepare spiritually, too: Saturday is the customary day for going to Confession, a "weekly cleaning" that readies one for the Sunday reception of the Eucharist.

Make Sundays a day for something special to the family, something your children will look forward to.

For dinner, have a special "Sunday food" that pleases all and becomes a family tradition -- a special bread, cake, pie, or other dessert. If you always eat in the kitchen, eat in the dining room on Sundays, and dress it all up with a tablecloth, low lighting, "nice" (at least pretty) china, a nice wine, and softly-played music that uplifts or is relevant to your ethnic heritage. At the table, the mother can light candles (why not a candle for each person at the table, or 7 candles in honor of the Sacraments and Moses' candelabrum in Exodus 25?). ²  You could even incorporate some special little symbolic thing to set on your table only on Sundays -- a little figurine, perhaps -- something that, when seen, marks the occasion as "set aside and special, and evokes all such occasions that were had in the past.

Back in the day, Italian-American extended families would all gather together, typically at Nonna's house, after Mass and prepare a huge meal. In our family, it was spaghetti feasts attended by Grandma, Grandpa, six of their seven children, those childrens' spouses, and those children's children. It made for a lot of people! Alas, large extended families are getting rare in the West given that people are having fewer children, and what children they do have often move away for economic reasons. Sad.

In any case, don't forget to begin the meal with the Prayer before Meals, and end it with the Prayer After Meals (the latter prays for the faithful departed, and the souls of our ancestors and loved ones should never be forgotten)! Just after the Prayer Before Meals, father can ritually bless his children and offer a prayer to sanctify domestic life. I recommend the following blessing and prayers (which includes a prayer to the Holy Family and the accclamation from the Introit of 4 June). Fathers, please consider praying these prayers in Latin!

Prayer before Meals
Benedic, Domine, nos et haec tua dona quae de tua largitate sumus sumpturi. Per Christum Dominum nostrum. Amen.	Bless us, O Lord, and these Thy gifts which we are about to receive from Thy bounty, through Christ, Our Lord, amen.
Father's (or Mother's) Blessing for Children
May Almighty God, Father, Son, and Holy Ghost, bless you, my child(ren), for time and eternity, and may this blessing remain forever with you. Amen
Prayer to the Holy Family, and Acclamation, Before Eating Sunday Dinner
Domine Iesu Christe, qui Mariae et Ioseph subditus, domesticam vitam ineffabilibus virtutibus consecrasti: fac nos, utriusque auxilio, Familiae sanctae tuae exemplis instrui et consortium consequi sempiternum: Qui vivis et regnas in saecula saeculorum. Amen. Quam bonus Israel Deus: his, qui recto sunt corde!	Lord Jesus Christ, Who, being made subject to Mary and Joseph, didst consecrate domestic life by Thine ineffable virtues; grant that we, with the assistance of both, may be taught by the example of Thy Holy Family and may attain to its everlasting fellowship. Who livest and reignest forever. Amen. How good is God to Israel: to them that are of a right heart!
Prayer after Meals
Agimus tibi gratias, omnipotens Deus, pro universis beneficiis tuis, qui vivis et regnas in saecula saeculorum. Fidelium animae, per misericordiam Dei, requiescant in pace. Amen.	We give Thee thanks for all Thy benefits, O Almighty God, Who livest and reignest forever. And may the souls of the faithful departed, through the mercy of God, rest in peace. Amen.

I strongly urge adopting practices that are done only on Sundays so that the day is set apart from all others in a very special way. Some suggestions:

• Pray with one another, especially the Rosary or a favorite chaplet
  
  
• Read to each other and with one another (why not engage in a little Lectio Divina?)... Read plays with each person taking a part, have Storytime (there is nothing better than being read to, and when children are read to, it encourages them to read!)
  
  
• Have a picnic
  
  
• Forbid smartphones altogether on Sundays
  
  
• Have a Cream Tea on Sunday afternoons. Invite other Catholics over and socialize a bit.
  
  
• Buy or cut fresh flowers on Saturday to adorn the house through the week
  
  
• Take a walk in the park
  
  
• Build a bonfire
  
  
• Sing together, otherwise make music together -- and listen to great music together
  
  
• Engage in crafts together
  
  
• Visit the The Domestic Church: The Catholic Home page and scroll down to find downloadable pages of questions you can discuss and games you can play around the dinner table. Invest, as well, in really good board and card games.
  
  
• Turn off the TV, or, if you "must," watch older movies. Or consider listening to old time radio shows which invite more imagination (see these pages, offsite: Yesterday USA and Old Time Radio for Downloading or Listening Online. Will open in new browser window). Better yet, make your own "radio" shows, complete with Foley effects and music, etc.

Take time to breathe deeply and watch your children playing in the yard, thinking to yourself, "This is good. Very good. Thank you, God."

Please see this page to read a lovely article by Sabine Barnhart about her memories of Sundays in Germany. The article, originally published at LewRockwell.com (and duplicated here with Mrs. Barnhart's permission), captures something of the "spirit of Sundays" and conveys what I'm trying to express about setting Sundays apart and making them special.

And read about Sundays in a piece written by Maria Von Trapp (of the Trapp Family Singers, "Sound of Music" fame).

See also the Mass's Attire and Etiquette page for tips on getting your children to pay attention and be still during Mass.


 

Footnotes:
¹ Most Catholics tend not to use the word "Sabbath" in reference to the Lord's Day, but typically use it instead to refer only to the Jewish Sabbath. Also note that because Christians use the term "Lord's Day" instead of "Sabbath," and because Saturday is the Jewish Sabbath, "Sabbatum," in Latin, means "Saturday." 

² Don't confuse the Mosaic 7-branched candlestick (a menorah) with the 8- or 9-branched channukiah (usually mistakenly also called a menorah) that post-Temple Jews use during Channukah celebrations.