Whereas the household altar is of high importance for the spiritual life of the oikos, there is no doubt that another part of the house served as a very important part of spiritual life, that of the entrance of the oikos. Anciently this could be a gate or a door. For most of us these days this is the front door of the house given that we do not live in courtyard based household schematics for the most part. A few ancient plays portray an address to the gods before the doorway, often before a momentous transition to come to the household. In these cases the gods of the doorway are more or less reminded of the offerings and propitiation given in the past at their stations. Such deities are typically liminal and are directly involved in transition and movement of state of being, and a kind of boundary crossing themselves. Typically gods associated with the with the doorway are Apollon (Agyieus/Prostaterios specifically), Artemis (Propthyria), Hekate, Hermes and Herakles. In my household I also include Leto (who is both a child giving goddess and underworld goddess), Dionysos (the god of transcendence and spiritual liberation), and Pan (who is particularly associated with the entrance of the temple of Apollon Karneios but represents the boundaries too between the dwelling of men with their pastures and the hidden wilderness, similar to some manifestations of Apollon.
Given the transitional nature of the doorway, and how it operates when we speak of a passage between life and death in which the dead may join ancestors and new life enter through birth into the oikos, the doorway serves as important spiritual passage. I have come to the conclusion that the best time to give oneself to devotions and prayers to the gods of the doorway is at the transition of days, as one day leads into the next (likewise it could be said that specific seasonal transitions that could be observed at the solstices and equinoxes if one chose can also be important occassions at the doorway as is the Noumenia, the first day of the lunar month which hails Apollon Noumenios particularly, likely at his domestic station before the doors). In the Hellenic oikos this transition of days occurs at sunset. Therefore this makes the time of the evening an important time of the day to give over to worship at the doorway to pray for the doors to be secure through the night, and that the gods before the doors draw forth good fortune and repel the bad from the oikos. It is in essence an asking of the blessings for the day to be addressed by the gods who dwell there, and providing offerings in thanksgiving to this which they do. Anciently it can be inferred that the gods of the doors were given offerings on the comings and goings of members of the oikos. Yet it is likely that was not quite as frequent as it is now. Any work/tasks done outside of the house was quite probably done in long stretches, after which an offering upon finally returning home would have been appropriate. In this day and age with the convenience of modern transportation we are more likely to flit to and from the house more than what would occur to us to supply offerings for each return back to the oikos. Therefore in my mind, a minimal observation in the evening, a time of day in which most of employed individuals are often returning home anyway, as representing the important transition of things, that if one were to boil a particular singular time of day to give honor to the gods at the doorway, this would be it.