| Sioux Falls Cayce | Eastern Time | -01:00 |
| Sioux Falls Cayma District | Peru Time | 00:00 |
| Sioux Falls Cazzago San Martino | Central European Time | -07:00 |
| Sioux Falls Caulfield North | Eastern Australia Time | -15:00 |
| Sioux Falls Caulfield South | Eastern Australia Time | -15:00 |
| Sioux Falls Caversham | Western Australia Time | -13:00 |
| Sioux Falls Cavan | Ireland Time | -06:00 |
| Sioux Falls Cavasso Nuovo | Central European Time | -07:00 |
| Sioux Falls Cave Creek | Mountain Time | 02:00 |
| Sioux Falls Chimney Rock | Eastern Time | -01:00 |
| Sioux Falls Chimgan | Uzbekistan Time | -10:00 |
| Sioux Falls Chilmark | Eastern Time | -01:00 |
| Sioux Falls Chiloquin | Pacific Time | 02:00 |
| Sioux Falls Chinon | Central European Time | -07:00 |
| Sioux Falls Cadiz | Central Time | 00:00 |
| Sioux Falls Castle Hills | Central Time | 00:00 |
| Sioux Falls Castlerigg | United Kingdom Time | -06:00 |
| Sioux Falls Castleisland | Ireland Time | -06:00 |
| Sioux Falls Castlemaine | Eastern Australia Time | -15:00 |
| Sioux Falls Catlettsburg | Eastern Time | -01:00 |
| Sioux Falls Catoosa | Central Time | 00:00 |
| Sioux Falls Casula | Eastern Australia Time | -15:00 |
| Sioux Falls Byford | Western Australia Time | -13:00 |
| Sioux Falls Byrdstown | Central Time | 00:00 |
| Sioux Falls Byrnihat | India Standard Time | -10:30 |
| Sioux Falls Byron | Eastern Time | -01:00 |
| Sioux Falls Byron Bay | Eastern Australia Time | -15:00 |
| Sioux Falls Bytča | Central European Time | -07:00 |
| Sioux Falls Cabazon | Pacific Time | 02:00 |
| Sioux Falls Cabarete | Atlantic Time | -01:00 |
| Sioux Falls Cabudare | Venezuela Time | -01:00 |
| Sioux Falls Cabrils | Central European Time | -07:00 |
| Sioux Falls Cabramatta | Eastern Australia Time | -15:00 |
| Sioux Falls Cabrerets | Central European Time | -07:00 |
| Sioux Falls Cabo de Gata | Central European Time | -07:00 |
| Sioux Falls Cadereyta Jiménez | Central Time | 00:00 |
| Sioux Falls Cadalso | Central European Time | -07:00 |
| Sioux Falls Cadalso de los Vidrios | Central European Time | -07:00 |