Call it whatever you want to, but for those of you new to LD cycling, do be aware that there are two conventions that you'll find many riders adhere to:
1. A ride of any length only gets reported as being of that length if it's relatively continuous. This is fuzzy, of course. Most people would not report two, 50-mile rides separated by 8 hours of sleep as a century ride, even if the rider reported the 8 hours of sleep in his or her total time. As I indicated above, I'd count your ride. A 3-hour break isn't out of the ordinary. Others wouldn't. That's cool.
2. On a related note, most LD riders expect that in reporting "how long it took to do the ride" that the rider is reporting the total elapsed time from start to finish. Any Fred can ride a "5 hour century" if he counts only his saddle time. Reporting only saddle time (and the related sin of talking about "average speed," a truly useless metric) is something for the Road forum, not here in LD.
