When people say '24/7', they mean '24 hours a day, 7 days a week' - "24 hours a day [during/for each of] 7 days a week" - a "cycle series" run/span of time.
Hence:
'24/7' = '24 hours a day, 7 days a week'
'24/7/52' = '24 hours a day, 7 days a week, 52 weeks a year'
'24/7/365' = '24 hours a day, 7 days a week, 365 weeks a year...???'
(This apparent breaking of the pattern is why I wrote what I did.)