Looks like Xbox online systems were down today, ranging from everything from gameplay to being able to buy anything. Naturally any online games like Destiny and Halo were useless during the 5 hour time span.
Microsoft hasn't said why it was down, but we'll update soon upon their announcement.
It's never fun when XBL goes down, although I no longer have my XB One, I do remember the frustration of wanting to play and seeing the service down. Will have to grab another console in the near future!