With the 2025 time change just taking into effect, we thought we’d dive into the details of Daylight Saving Time (DST). Why do we change our clocks twice a year? Which areas follow DST time? And more DST details below.
What is Daylight Saving Time?
Simply put, Daylight Saving Time is changing the clock one hour ahead in the spring (to DST) and back an hour in the fall (to standard time). A common mnemonic device to help remember which way to change the clock is to “spring ahead” and “fall back” due to the seasons in which these time changes occur.
Daylight Saving Time was introduced in the United States in the Standard Time Act of 1918 with laws and dates changing multiple times since then. Although national observances came and went throughout the years, the “energy crisis” in 1974 began more strict regulations to change the clocks in order to reduce energy usage at night. More changes followed due to “side effects” until 2007 when the DST dates became the second Sunday in March to the first Sunday in November, which is what we follow today.
Where Recognizes Daylight Saving Time?
Even though DST (or a similar form of “summer time”) is typically observed in most of the United States, Canada, and other countries in the northern hemisphere, there are some states/areas that do not. Most notably, Hawaii, most parts of Arizona (except the Navajo Nation), American Samoa, Guam, Puerto Rico, and the US Virgin Islands do not.
Durango and Daylight Saving Time
As Durango does observe DST, it comes with great benefits as well as some negative aspects. In the summer, after we’ve “sprung ahead”, we get an “extra” hour of daylight perfect for enjoying all of the outdoor activities in our area. However, in the winter, after “falling back” an hour, the day is even shorter paired with earth’s natural rotation. It’s not uncommon to get up before the sun rises and to leave work near dusk.
There is about a five hour difference of daylight between the summer solstice and winter solstice in Durango. Although five hours is substantial, more northern areas such as in Washington, Montana, and North Dakota experience over seven hours difference from summer to winter.
How Does Daylight Saving Affect Time Zones?
Across the globe, time zones are based on longitude in relation to England's Greenwich Observatory which creates Greenwich Mean Time (GMT) also known as Coordinated Universal Time (UTC) as it’s located along the Prime Meridian. Every 15 degrees east or west of the Prime Meridian adds or subtracts an hour, creating 24 equal parts. However, the time zone lines are altered more due to internal and international borders, politics, and traditions. Today, there are 38 time zones used across the world. The United States technically has 11 time zones in use but commonly uses four for the contiguous states: Pacific Standard Time, Mountain Standard Time, Central Standard Time, and Eastern Standard Time.
Since Durango, CO is officially Mountain Standard Time (MST) but observes DST, from the second Sunday in March to the first Sunday in November, it is referred to as MDT or Mountain Daylight Time. However, since the majority of Arizona is also MST but doesn’t participate in DST, they always stay on MST.
Whether you are moving to Southwest Colorado or leaving the area, it’s important to know what regimes the area follows so you’re not an hour early (or late!) for an appointment. Luckily, our phones and other devices typically auto-update based on geographic location, but you still usually need to manually update analog watches, stove displays, coffee makers, etc. For more local information, please reach out to the Durango Team at The Wells Group.
