This is something that has been on my mind today, and some of yesterday given it is Sunday. I have recently moved around my weekly schedule. At one point I was celebrating Sundays for Apollon, this was a practice started initially because of my long time participation in kyklos Apollon which was timed to Delphi sunrise on Sunday. However, under consideration of several factors I changed it up. For one I worship Helios-Surya on Sundays, and because I do not, unlike fellow worshipers who do agree with late period perspective in which Apollon and Helios were considered the same god, see Apollon as being Helios, or anything near similar to Helios.
Although Apollon has several epithets that address light and illumination, most of his mythic (that which is not originals myths of Helios that were later adapted with Apollon in the place of Helios) and cultic presence has nothing to really do with the sun. In myth we find two instances were the sun may have of some importance….the most obvious is that myth of the dragoness Delphyne in which Apollon rots her body with the heat of the sun, and the other is a speculation that in the myth of Hyakinthos that the “disc” he slayed the prince with in an allusion to the sun killing the tender growth of spring. In either case Apollon himself is not identified in any fashion with Helios, rather then directs the power of Helios to his purpose. This suggests that while Helios may be considered an “ally” of Apollon, they cannot really be considered synonymous from this standpoint. Rather than sun god, Apollon has more evident presence as a god of the boundaries (boundaries of the household, between the world of the living and dead/cemeteries etc), purifier/destroying god/sustainer of harmonic balance and movement, healing, caretaking of flocks and crops by which he protects us from famine, passage of time by which he is also a boundary god as a god of twilight which oversees the time periods of alternating day and night/moon and sun passage which would correspond his oversight over the passage of seasons as per the Orphic hymn the observation of which is necessary toward the end of agricultural based civilization. As such he is a god of endings as we see in his function as destroyer and opening the door to new beginnings as we see him as Apollon Noumenios. Understanding this lets us understand how some of heraldic animals directly indicate this by their liminal natures, such as the mouse, the wolf, the serpent etc.
Rather than solar, it is perhaps more accurate to say that he is “fiery.” Fire being both a nurturing and destroying element it would by its quality of illumination be linked indirectly to all light bearing bodies of the heavens by which we see Apollon’s association with the polar store/axis of the heavens, the moon and the sun in an indirect manner. Fire is an element associated with purification (consider the lustral water of Hellenic religion in which the water is made sacred by extinguishing flame in the water), its association with health and wellbeing, and its connection with foodmaking. Given that in the Hyakinthia that bread was forbidden in the mourning of the prince, it is reasonable to see Apollon associated here with foodproduction as the very force which protects the crops of grain by destroying all that which would deplete prematurely. Thus the success of the crops is attributed to him, not as a solar god, but as a destroying liminal boundary god who sees and hears in all directions. Lord of the axis off the heavens who directs the heavenly bodies, the sinking and rising of constellations with the seasons, the rise and sinking of the sun and moon by day and night. As lyre player he leads forth the whole chorus and dance, a difference between the that and the harp of the sun as we find in the Orphic hymn of Helios which issues in a way which can be imagined as the beautiful melody of the day. Even the chariot of Apollon is rarely depicted as pulled by horses, which are particularly sacred to Helios and the only beast to pull his chariot, but rather by swans, griffins, or some kind of chthonic creature such as boar and serpent. Deer and most especially goats probably have the same kind of prestige as we find with the horse for Helios. This is to not say that the horse never appears with Apollon, but that it is very rare outside of cases where Apollon is taking the place of Helios.
As a pinnacle of our world’s life, we can certainly see a basis for the alliance between Apollon and Helios. But this does not, in my book, make them the same and equivalent. Therefore just as the day between the Noumenia kata Selene and the Deipnon we find a day for reverence of the sun, followed by the day of Apollon Noumenios which officially begins the new month, therefore sunday (which is technically part of the weekend) is dedicated to Helios-Surya, and Monday is, for the opening of the new week, for Apollon-Siva, the fiery lord who is offered copious cool libations and sweet fumigation of incense