It's important to understand that, Sabbath is not a day, the Hebrew word means simply rest. Originally Sabbath was a day that people were required to rest from all of their work, to stay at home with their families and were not allowed even to walk a certain distance.

However, some Sabbaths were designated as special Sabbaths and people were allowed to go to the temple for sacrifice offerings and a holy assembly. Making Sabbaths as days where people go to the 'synagogues' for worship is a later invention mainly post-exilic jewish custom. The notion of Sabbath teaches us some very important Biblical truths:
1. It is important to rest where you have a day you cease from all what you have been doing throughout the week. This is divine.
2. Resting should be used to remember and worship God who is the creator of the universe. Actually, Sabbath remembrance emphasizes God as the creator, and this is very important teaching modern people should get.
3. The New Testament philosophy on Sabbath reflects on the meaning (i.e. rest) rather than arguments about a particular day. Christ is our true Sabbath (i.e. rest), and this is the teaching of the New Testament (Matt.11:27-29).
4. However, for a Christian to have Sunday as a Sabbath, gives more meaning to him as on that day Christ raised from the dead the first fruit of those who are asleep.

Thanks.