I believe the description was updated in the meantime:

... return it with its digits in descending order.

Comments are things to be ignored when compiling
For example you would not preserve comments in C to the byte code
So likely, this line could be simply dropped when parsing

Three years and a couple thousand solutions further, it hasn't been fixed. I guess it's not going to be fixed.

Closin.

client might not care but the next developer after you would. lol.

What????

While it may be faster, its a little more difficult to read and understand what you're doing. There's more to best practices than faster code.

So without specifying 'self' it just forwards it to the existing upcase method?

But the lead solution is far easier to understand, a lot shorter and becouse of that faster to read.
Coding is not just about writing fast code :)

The user-defined function all is not the same as the Enumerable#all? method.

w00p w00p! I had the same solution as yours.

I think ours is more readible

The Kata description explicitely states: "The start time will always be before the end time."

Also AM/PM has nothing to do with this. "Time is stored internally as the number of seconds with fraction since the Epoch, January 1, 1970 00:00 UTC"