The states that observe daylight saving time are:
1. Connecticut
2. Illinois
3. Nevada
4. Wyoming
Arizona, Alaska, Hawaii do not observe daylight saving time.
Daylight saving time is the practice of setting the clock forward by one hour during the warmer months to extend evening daylight. Some states and countries choose to observe daylight saving time, while others do not. In the United States, the decision to observe daylight saving time is determined by individual states.