Sunrise and Sunsetat University of Colorado Boulder
Friday, 12 September 2025
Sunrise
6:39 AM
Sunset
7:14 PM
On 12 September, the sun rises at 6:39 AM and sets at 7:14 PM.
The sun is 12 hours 34 minutes above the horizon (the length of the day).
Astronomical dawn (first rays of light) begins at 5:07 AM and at 8:46 PM it is completely dark (the end of astronomical twilight).
The sun is 12 hours 34 minutes above the horizon (the length of the day).
Astronomical dawn (first rays of light) begins at 5:07 AM and at 8:46 PM it is completely dark (the end of astronomical twilight).
| Date | Sunrise | Sunset | Day length |
|---|---|---|---|
| 1 September 2025, Monday | 6:29 AM | 7:32 PM | 13h 03m |
| 2 September 2025, Tuesday | 6:30 AM | 7:30 PM | 13h 00m |
| 3 September 2025, Wednesday | 6:31 AM | 7:29 PM | 12h 57m |
| 4 September 2025, Thursday | 6:32 AM | 7:27 PM | 12h 55m |
| 5 September 2025, Friday | 6:33 AM | 7:26 PM | 12h 52m |
| 6 September 2025, Saturday | 6:34 AM | 7:24 PM | 12h 50m |
| 7 September 2025, Sunday | 6:35 AM | 7:22 PM | 12h 47m |
| 8 September 2025, Monday | 6:35 AM | 7:21 PM | 12h 45m |
| 9 September 2025, Tuesday | 6:36 AM | 7:19 PM | 12h 42m |
| 10 September 2025, Wednesday | 6:37 AM | 7:17 PM | 12h 40m |
| 11 September 2025, Thursday | 6:38 AM | 7:16 PM | 12h 37m |
| 12 September 2025, Friday | 6:39 AM | 7:14 PM | 12h 34m |
| 13 September 2025, Saturday | 6:40 AM | 7:12 PM | 12h 32m |
| 14 September 2025, Sunday | 6:41 AM | 7:11 PM | 12h 29m |
| 15 September 2025, Monday | 6:42 AM | 7:09 PM | 12h 27m |
| 16 September 2025, Tuesday | 6:43 AM | 7:07 PM | 12h 24m |
| 17 September 2025, Wednesday | 6:44 AM | 7:06 PM | 12h 21m |
| 18 September 2025, Thursday | 6:45 AM | 7:04 PM | 12h 19m |
| 19 September 2025, Friday | 6:46 AM | 7:02 PM | 12h 16m |
| 20 September 2025, Saturday | 6:47 AM | 7:01 PM | 12h 14m |
| 21 September 2025, Sunday | 6:48 AM | 6:59 PM | 12h 11m |
| 22 September 2025, Monday | 6:49 AM | 6:57 PM | 12h 08m |
| 23 September 2025, Tuesday | 6:50 AM | 6:56 PM | 12h 06m |
| 24 September 2025, Wednesday | 6:51 AM | 6:54 PM | 12h 03m |
| 25 September 2025, Thursday | 6:52 AM | 6:53 PM | 12h 00m |
| 26 September 2025, Friday | 6:53 AM | 6:51 PM | 11h 58m |
| 27 September 2025, Saturday | 6:54 AM | 6:49 PM | 11h 55m |
| 28 September 2025, Sunday | 6:54 AM | 6:48 PM | 11h 53m |
| 29 September 2025, Monday | 6:55 AM | 6:46 PM | 11h 50m |
| 30 September 2025, Tuesday | 6:56 AM | 6:44 PM | 11h 47m |