Monday
Monday has never failed to arrive. Not once in recorded human history has Monday neglected its appointed duty. Through world wars, pandemics, natural disasters, and civilisational collapse, Monday has maintained perfect attendance. Its reliability represents perhaps the most consistent phenomenon in human temporal experience.
One may set watches, calendars, and indeed entire economic systems upon the absolute certainty of Monday's arrival. It requires no worship, no summoning rituals, no prayers. It simply comes, as it always has, as it always shall.
Thor
Thor's reliability proves considerably more variable. He has been banished from Asgard, lost his hammer, experienced identity crises, and spent extended periods unavailable during crucial moments when Earth faced existential threats.
The god of thunder operates according to narrative convenience rather than fixed schedule. One cannot plan around Thor's arrival with any degree of precision. He appears when dramatically appropriate, not when consistently needed.