"In 1 Corinthians 16:1–3, the apostle Paul writes,
something aside” until he could send helpers to transport the collection to Jerusalem. The expression "lay something aside" in the original Greek comes with the connotation of putting something aside at home. Even Sunday-worship advocates agree with this interpretation.
Thus, there was no religious meeting held on the first day of the week and no collection plate passed at church on Sunday. Instead, they were to gather and store up their donations at home on that day.
If there was no religious meeting on Sunday, why did Paul specifically suggest that this work be done on Sunday? Simply, the letter would have been shared with the church on the Sabbath when they were all gathered for worship, and the first opportunity for them to do the work would be the next day—the first day of the week."
SabbathTruth
“Now concerning the collection for the saints, as I have given orders to the churches of Galatia, so you must do also: On the first day of the week let each one of you lay something aside, storing up as he may prosper, that there be no collections when I come. And when I come, whomever you approve by your letters I will send to bear your gift to Jerusalem.”
In this passage, the apostle was writing a special appeal to the churches in Asia Minor. Famine conditions were not unusual in areas of the Middle East (see Acts 11:28–30), and at the time, many of the Christians in Jerusalem were suffering greatly. Paul asked the church at Corinth to “lay 
Thus, there was no religious meeting held on the first day of the week and no collection plate passed at church on Sunday. Instead, they were to gather and store up their donations at home on that day.
If there was no religious meeting on Sunday, why did Paul specifically suggest that this work be done on Sunday? Simply, the letter would have been shared with the church on the Sabbath when they were all gathered for worship, and the first opportunity for them to do the work would be the next day—the first day of the week."
SabbathTruth