Something you won’t meet in real life. At least, you won’t meet it except by pure luck in affordable web hosting.
Just in case you’ve never run the numbers…
| Year | Minutes |
|---|---|
| 1 | 525,600 |
| .1 | 52,560 |
| .01 | 5,256 |
| .001 | 525.6 |
| .0001 | 52.56 |
| .00001 | 5.256 |
So there you have it. Being up .99999 of the time (over a year) means you can have just over 5 minutes of downtime. Total. The whole year. (This being a 365 day calendar year, not an astronomical year.)