I don't know take your pick or flip a coin.
In reality its the quality of the particular
school and its training more than the piece of paper.
No
certification is required for UK unless its a
commercial operation. So the Day Night thing doesn't matter. It's a recommendation giving you an idea what is covered and what you should be comfortable with after having taken the course.
In many ways the RYA is being a bit more realistic. Suggesting as the box says.
You will be ready to Skipper a
boat by Day.
A basic entry level giving you the knowledge to sail a small
sail boat in familiar
water in Daylight. Is a good place to start.
You can build on it later. As you gain experience. By taking course's, reading
books or sailing with friends.
Truthfully, In a similar course time, the amount of time given to night sailing would be very minimal. You might get an overnight
passage in. You might not depends on itinerary.
I used to teach CYA, quite often we included an overnight
passage. On one hand It was mostly a long cold night.
On the other hand I was able to show students some simple things and take the mystery out of it having crewed they might be more confident trying it later.
For most people. Sailing as a skipper at night is a big jump. Confidence being the hurdle. Unless they have crewed at quite regularly night. It's not really any harder. It some ways it easier.
The hardest bit is getting a good watch routine, and dealing with cold and fatigue.
A good prep, Do an online or classroom coastal
navigation course. RYA ect.
Have fun, Sailing is quite easy.