Availability percentages and yearly downtime

Availability percentage	24-hour day	8-hour day
90%	876 hours (36.5 days)	291.2 hours (12.13 days)
95%	438 hours (18.25 days)	145.6 hours (6.07 days)
99%	87.6 hours (3.65 days)	29.12 hours (1.21 days)
99.9%	8.76 hours	2.91 hours
99.99%	52.56 minutes	17.47 minutes
99.999% ("five nines")	5.256 minutes	1.747 minutes
99.9999%	31.536 seconds	10.483 seconds