Sierra Time Zone (S) is 6 hours behind Coordinated Universal Time (UTC). This time zone is a military time zone.
See full time zone mapWhere and When is S Observed?
Sierra Time Zone is often used in aviation and the military as another name for UTC -6. Sierra Time Zone is also commonly used at sea between longitudes 97.5° West and 82.5° West.
The letter S may be used as a suffix to denote a time being in the Sierra Time Zone, such as 08:00S or 0800S. This is spoken as "zero eight hundred Sierra".
The letter S may be used as a suffix to denote a time being in the Sierra Time Zone, such as 08:00S or 0800S. This is spoken as "zero eight hundred Sierra".
Some places with the same time as Sierra Time Zone
Other Time Zones in UTC -6
Some time zones exist that have the same offset as S, but can be found under a different name: