Curse of Strahd light cleric here. We're very early in the game and we just fought and killed 6 vampire spawn as 4 level 3 characters. This, obviously, could never actually happen but we were aided by the random occurrence of the effects of a daylight spell. The effects basically did the work for us while all of our efforts did almost nothing. As a result of this we are leveling up to level 4 where I have the daylight spell prepared at all times as a light cleric.

This seems like OVERKILL in this campaign, does the daylight spell actually do the full damage as indicated in Monster Manual:

"Sunlight Hypersensitivity. The vampire takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks."

The question here is: is daylight the same as sunlight?

No it is not:

http://www.sageadvice.eu/2016/03/02/does-the-spell-daylight-create-sunlight-against-vampires-drow/

If a spell creates sunlight, the spell should clearly say so, like the spell Sunbeam.

ya, as you can tell I agree with this interpretation because otherwise I'm going to waltz through this campaign using the Daylight spell over and over and over and over...

Radiance of the Dawn as a channel divinity option is nice in that it creates similar effects but it is instantaneous and I only get 2 uses of it/longrest at this point. 

I'm not sure if it's too late for you, but Channel Divinity is S/R and L/R. 

Best of luck with Strahd. Awesome fights and fun times.

Edit: Sorry Necro

You get 1 use of Channel Divinity per short rest, not 2 uses per long rest. At 6th lvl you get 2 uses per short rest and at 18th lvl 3 uses.

Daylight won't do the trick, but dawn (XGtE) will.

What about in the 2024 edition of the rules. Daylight spell description clearly describes the light from the Daylight spell as sunlight. Not daylight - that's just the spells name not it's effect. 

Copied and pasted from the Daylight spells disruption...

"For the duration, sunlight spreads from a point within range and fills a 60-foot-radius Sphere. The sunlight’s area is Bright Light and sheds Dim Light for an additional 60 feet.

Alternatively, you cast the spell on an object that isn’t being worn or carried, causing the sunlight to fill a 60-foot Emanation originating from that object. Covering that object with something opaque, such as a bowl or helm, blocks the sunlight.

If any of this spell’s area overlaps with an area of Darkness created by a spell of level 3 or lower, that other spell is dispelled."

It clearly states 'sunlight' not daylight, or light, or illumination, or another word that could have been used to describe the type of light conjured from the spell. So I would be inclined to believe that Daylight would hurt vampires, effect Dorw or any other creature that was subject to special rules due to 'sunlight' - seem pretty clearly by RAW.  

Sunlight is sunlight. The spell was changed and got a bit of a buff.