Boise time zone history
Boise left local mean time (UTC−7:44:49) in 1883, tied for the earliest switch among the 11 zones on UTC−7 standard time with local mean time in the record. Clocks have been changed 114 times since 1970, tied for the most among the 12 zones on UTC−7 standard time.
UTC−7
Standard time is UTC−7 (MDT/MST); clocks go forward to UTC−6 on the second Sunday in March and back on the first Sunday in November.
Summer time in every year since 1970
Before 1970
Standard time changes
| Date | Change | New standard time | Clock label |
|---|---|---|---|
| Before 1970 | |||
| November 18, 1883 | Local mean time (UTC−7:44:49) replaced | UTC−8 | PST |
| May 13, 1923 | Standard time forward 1 hour | UTC−7 | MST |
Daylight saving periods
| Years | Clocks go forward | Clocks go back | Shift and labels |
|---|---|---|---|
| Before 1970 | |||
| 1918–1919 | last Sunday in March, 02:00 | last Sunday in October, 02:00 | 1 hour, PST to PDT |
| 1942 | February 9 | not that year | 1 hour, MST to MWT |
| 1945 | not that year | September 30 | 1 hour |
| 1967–1973 | last Sunday in April, 02:00 | last Sunday in October, 02:00 | 1 hour, MST to MDT |
| Since 1970 | |||
| 1974 | February 3 | October 27 | 1 hour, MST to MDT |
| 1975 | February 23 | October 26 | 1 hour, MST to MDT |
| 1976–1986 | last Sunday in April, 02:00 | last Sunday in October, 02:00 | 1 hour, MST to MDT |
| 1987–2006 | first Sunday in April, 02:00 | last Sunday in October, 02:00 | 1 hour, MST to MDT |
| 2007–2037 | second Sunday in March, 02:00 | first Sunday in November, 02:00 | 1 hour, MST to MDT |
Clock changes in 2026, 2027 and 2028
The clocks go forward 1 hour (MST to MDT) on March 8, 2026, March 14, 2027 and March 12, 2028 at 02:00 and back 1 hour (MDT to MST) on November 1, 2026, November 7, 2027 and November 5, 2028 at 02:00, local time.
Also on UTC−7
Vancouver (Canada), Denver (United States), Phoenix (United States), Dawson Creek (Canada), Ciudad Juárez (Mexico), Hermosillo (Mexico), Fort Nelson (Canada), Whitehorse (Canada), Mazatlan (Mexico) and Dawson (Canada) (nearest first; 1 more on the list of offsets).
Clocks next door since 1970
- Vancouver (Canada) (821 km): usually 1 hour behind; different on 212 days in 1970–2026; same time today.
- Swift Current (Canada) (975 km): same time except 8,533 days in 1970–2026; 1 hour ahead today.
- Denver (1,025 km): same time except 28 days in 1974.
- Los Angeles (1,078 km): usually 1 hour behind; different on 33 days in 1970–2026.
- Edmonton (Canada) (1,123 km): same time except 579 days in 1970, 1971, 1974, 1975 and 2026; 1 hour ahead today.
How it compares
Standard time has stayed at UTC−7 since 1923.
On standard time, clocks in Boise run 45 minutes ahead of local mean solar time.