Doctrine & Covenants 59:9-12

And that thou mayest more fully keep thyself unspotted from the world, thou shalt go to the house of prayer and offer up thy sacraments upon my holy day;
For verily this is a day appointed unto you to rest from your labors, and to pay thy devotions unto the Most High;
Nevertheless thy vows shall be offered up in righteousness on all days and at all times;
But remember that on this, the Lord’s day, thou shalt offer thine oblations and thy sacraments unto the Most High, confessing thy sins unto thy brethren, and before the Lord.
Doctrine & Covenants 59:9-12

Read in scriptures: http://bit.ly/2aRx5eL