Complete the pattern

I have often wondered how people come up with puzzle questions.  They must have to be really smart to figure them out.  I was thinking about this one night, while drifting off to sleep, and I came up with the following puzzle question of my own.  I don’t know how easy or hard it is, but here it is.  Complete the pattern:

10:10 10:11 10:12 10:13 10:15
10:10 10:11 10:15 10:13 ?

What time should appear in the last box?  Put you answer in the comments and your reason why, and I will let you know if it the same reason I came up with for my answer.