There are some references to the observance of certain days and seasons in the writings of the Apostolic Fathers, but there is no clear indication of a particular day or season being more significant than others in terms of Christian faith and practice.
For example, in the Didache (or Teaching of the Twelve Apostles), a Christian manual that may have been written around the late first or early second century AD, there are instructions for fasting and prayer, but no mention of specific days being more significant. Similarly, in the Epistle of Barnabas, which is believed to have been written in the late first or early second century AD, there are some references to the Jewish calendar but no clear emphasis on the observance of specific days in Christianity.
In the letters of Ignatius of Antioch, another early Christian writer believed to have lived in the early second century AD, there are some references to the celebration of Easter and other Christian festivals, but again no clear indication of a particular day or season being more significant than others.
Overall, while there are some references to the observance of specific days and seasons in the writings of the Apostolic Fathers, there is no clear emphasis on the importance of certain days in Christian faith and practice.