You're replying to a thread from 19 years ago. Even 3.5 wasn't a thing back then, never mind 5th edition!So the author and editor probably knew the rules, and not just the rules of 5th edition, but of pretty much all vampire lore ever, and reasonably felt the spell's name implied what it was.
So Find Traps actually find traps in your campaigns? Is Chill Touch a melee spell that does cold damage for you?DM discretion, such as when Chris Perkins allowed character Evelyn to have her Moonbeam be morning light. But with less of a stretch, as a DM, I rule that if a spell is called something, it is that thing. Therefore if the spell is called Daylight, it is actually Daytime Light. If a spell is called Sunbeam, it literally is a beam of Sun (in terms of light, not a beam of the heat or raw energy of a whole star). Otherwise, they should have called the spell Radiant Light, and Radiant Beam, or something else not pertaining to daytime or the sun, since, well, one might think in dealing with Curse of Strahd, that'd be a blatantly obvious point of needed clarity.
This thread doesn't seem to be tarring or joking loudly though.Wow, a 19-year thread necro is pretty impressive. Also impressive that ENWorld has kept around threads from that long ago and that they are still relevant.
I'll just point out that 5E doesn't directly answer the question of whether "daylight" and "sunlight" are the same. For example, is a vampire standing in the shade during the day going to take damage? That's clearly daylight but one could reason that it's not sunlight. Or, on a gray overcast day thick with clouds, would a vampire be taking damage? Again, that is clearly daylight, but arguably not sunlight. There's evidence in the text for both interpretations, but nothing conclusive, so it's up to the DM to decide.