Time in Idaho


The U.S. state of Idaho is covered by two time zones, as described below. All locations observe daylight saving time.

Blue portions are Pacific Time, magenta portions are Mountain Time.

The Pacific Time Zone (UTC−08:00, DST UTC−07:00) covers an area roughly coterminous with the Idaho Panhandle or North Idaho:

An easy way to distinguish the line is that it essentially follows the line that divides Washington and Oregon. Idaho counties east of Washington observe Pacific Time, and Idaho counties east of Oregon observe Mountain Time.

The Mountain Time Zone (UTC−07:00, DST UTC−06:00) covers the rest of the state.

History


The 1918 Standard Time Act put most of Idaho into the Pacific Time Zone  only the very eastern parts were in the Mountain Time Zone.[1]

For three decades or so in the middle of the twentieth century, Shoshone County had its own time arrangements; it was said to be "on permanent daylight time",[2] so that in the winter the county had the same clock time as Montana and southern Idaho, but in the summer it had the same clock time as Spokane and northern Idaho.

tz database


The tz database version 2021a contains two time zones for Idaho:

CC Coordinates TZ Comments UTC offset UTC offset DST Notes
US +340308−1181434 America/Los_Angeles Pacific −08:00 −07:00
US +433649−1161209 America/Boise Mountain - ID (south); OR (east) −07:00 −06:00

References


  1. Prerau, David (2006). Seize the Daylight: The Curious and Contentious Story of Daylight Saving Time. p. 91. ISBN 978-1-56025-796-7.
  2. "Time Zone Woe May Be Solved". Spokane Daily Chronicle. 1966-11-04. Retrieved 2016-05-31.