Nowhere in the scriptures do you find one word which sanctions Sunday worship, you can search in the Old as well as the New Testament there is nothing.
Very simple,
Do as the Catholics do. They have a daily mass and many people attend daily. End result.... they are certain to worship on a day that you claim God approves of.

Matthew 28:1, "After the sabbath, as the first day of the week was dawning, Mary Magdalene and the other Mary went to see the tomb. And suddenly there was a great earthquake...." Jesus was crucified on Friday.
Mark 16:9, "Now after he rose early on the first day of the week, he appeared first to Mary Magdalene, from whom he had cast out seven demons."This verse simply records that, after His resurrection early on the Sunday morning, Jesus appeared to Mary Magdalene.
Jesus' Resurrection....
Webster defines resurection as:
Definition of resurrection
1acapitalized : the rising of Christ from the dead
boften capitalized : the rising again to life of all the human dead before the final judgment
c: the state of one risen from the dead
FACT: Jesus rose after the Jewish Sabbath.
Why do you think that is? I submit because not only was it the first day of the week, it was because HE, and only HE offered a new beginning. A new beginning for those who would be following him in action and faith.
A new way. A new everything.
It is only proper that worship of Him would be separate from any other Jewish and or Pagan worships.
It separates us. It separates the wheat from the chaff if you would.
He offered us a new beginning. A new life. An everlasting life into eternity.
How WRONG it would be to try and blend that into any other religious days or practices.
Jesus said
Revelation 1:8 King James Version (KJV)
8 I am Alpha and Omega,
the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty.
repeated:
Revelation 22:13
“I am Alpha and Omega,
the beginning and the end, the first and the last.”
He began on the first day of the week.
He waited until the Passover Sabbath was ended and the weekly Sabbath was ended.
It is only proper for us to worship him on the day he began.... NOT after a week had gone by until Fri. sundown.
Jesus was crucified on Friday.
NO HE WAS NOT!This has been discussed in other threads. Do a search.