This doctrine of Sunday was codified at the Council of Nicaea in 325 CE with its many other anti-semitic regulations further separating the Jewish Sabbath from the Christian Sunday. In 363 CE, the Council of Laodicea prohibited Christians from observing the Biblical Sabbath and encouraged them to work on Saturday and rest on Sunday. The fact that this edict was issued with prohibitions indicates that Sunday worship was still not totally accepted by followers Yeshua.
Many Christians love to say “Happy Lord’s Day” on Sunday as a greeting of blessing to other believers. However, is the LORD’s Day really Sunday? Is celebrating the LORD’s Day a blessing?