Daily Edition: The Lord's Day Evening / by Shane Anderson

In past generations, the common practice of biblical churches was to bookend the Lord's Day with worship: morning and evening. While this practice has largely fallen into neglect and is often portrayed as an archaic legalism, the more confessionally minded Reformed churches tend to continue the practice.

From the Orthodox Presbyterian Church's Directory For Public Worship: 

The Lord's Day is a day of holy convocation, the day on which the Lord calls his people to assemble for public worship.

a. Although it is fitting and proper that the members of Christ's church assemble for worship on other occasions also, which are left to the discretion of particular sessions [note: not to the individual believer], the Lord calls the whole congregation of each local church to the sacred duty and high privilege of assembling for public worship each Lord's Day. He expressly commands his people to draw near to him, not forsaking the assembling of themselves together.

b. It is highly advisable that a congregation assemble for public worship at the beginning and the ending of the Lord's Day. God established this pattern for his Old Testament people when he commanded morning and evening sacrifice and incense burning. Moreover, he sanctifies the entire Lord's Day to himself and gives his people in it a foretaste of their eternal enjoyment of him and his people.

Here is a selection of some resources exploring the topic:

"The Death of the Evening Service" by Mark Jones via reformation21

"Are Evening Worship Services a Matter of Personal Preference for God’s Children?" by William J. Vermeulen

"Recovering the Lost Treasure of Evening Worship" by Jon Payne via Modern Reformation

"The Evening Service" by Robert S. Rayburn

"Let's Keep Our Sunday Evening Worship" by Paul H. Alexander via the OPC

"Attendance at Morning and Evening Worship" from Wes Bredenhof

"Why An Evening Worship Service?" by Christ United Reformed Church