No DST
1970 - 2030
| No further time changes in 1989 in Sierra Vista |
Daylight Saving Time (DST) Not Observed in Year 1989
USA observed Mountain Standard Time (MST) all year.
Daylight Saving Time has not been used since our records start, in 1970.
DST data from before 1970 is not available for Sierra Vista, USA. However, we have earlier DST history for Phoenix, USA available.