3U9 Boulder night times
Boulder, MT
Night of Nov 6 to Nov 7MST
Position lights
§ 91.2095:07 PMto7:18 AM
Sunset to sunrise. Lights on.
0007Z to 1418Z
Night logging
§ 1.15:38 PMto6:46 AM
Civil twilight. Log it as night.
0038Z to 1346Z
Night currency
§ 61.57(b)6:07 PMto6:18 AM
One hour after sunset. Landings count.
0107Z to 1318Z
Evenings at 3U9
When each night begins, through the year. Local time.
| Date | SunsetLights on | Civil twilight endsLog night | 1 hr after sunsetLandings count |
|---|---|---|---|
| Nov 1MST | 5:14 PM | 5:45 PM | 6:14 PM |
| Nov 15MST | 4:56 PM | 5:28 PM | 5:56 PM |
| Dec 1MST | 4:44 PM | 5:18 PM | 5:44 PM |
| Dec 15MST | 4:43 PM | 5:18 PM | 5:43 PM |
| Jan 1MST | 4:53 PM | 5:28 PM | 5:53 PM |
| Jan 15MST | 5:09 PM | 5:43 PM | 6:09 PM |
| Feb 1MST | 5:33 PM | 6:05 PM | 6:33 PM |
| Feb 15MST | 5:54 PM | 6:25 PM | 6:54 PM |
| Mar 1MST | 6:15 PM | 6:45 PM | 7:15 PM |
| Mar 15MDT | 7:34 PM | 8:04 PM | 8:34 PM |
| Apr 1MDT | 7:57 PM | 8:28 PM | 8:57 PM |
| Apr 15MDT | 8:16 PM | 8:47 PM | 9:16 PM |
| May 1MDT | 8:37 PM | 9:10 PM | 9:37 PM |
| May 15MDT | 8:55 PM | 9:30 PM | 9:55 PM |
| Jun 1MDT | 9:13 PM | 9:50 PM | 10:13 PM |
| Jun 15MDT | 9:22 PM | 10:01 PM | 10:22 PM |
| Jul 1MDT | 9:24 PM | 10:02 PM | 10:24 PM |
| Jul 15MDT | 9:17 PM | 9:54 PM | 10:17 PM |
| Aug 1MDT | 8:59 PM | 9:33 PM | 9:59 PM |
| Aug 15MDT | 8:38 PM | 9:10 PM | 9:38 PM |
| Sep 1MDT | 8:07 PM | 8:38 PM | 9:07 PM |
| Sep 15MDT | 7:40 PM | 8:10 PM | 8:40 PM |
| Oct 1MDT | 7:09 PM | 7:38 PM | 8:09 PM |
| Oct 15MDT | 6:42 PM | 7:12 PM | 7:42 PM |
Mornings at 3U9
When each night ends. Local time.
| Date | 1 hr before sunriseLandings stop counting | Civil twilight beginsNight logging ends | SunriseLights off |
|---|---|---|---|
| Nov 1MST | 6:10 AM | 6:38 AM | 7:10 AM |
| Nov 15MST | 6:30 AM | 6:57 AM | 7:30 AM |
| Dec 1MST | 6:51 AM | 7:17 AM | 7:51 AM |
| Dec 15MST | 7:05 AM | 7:30 AM | 8:05 AM |
| Jan 1MST | 7:11 AM | 7:37 AM | 8:11 AM |
| Jan 15MST | 7:07 AM | 7:33 AM | 8:07 AM |
| Feb 1MST | 6:51 AM | 7:19 AM | 7:51 AM |
| Feb 15MST | 6:32 AM | 7:01 AM | 7:32 AM |
| Mar 1MST | 6:08 AM | 6:38 AM | 7:08 AM |
| Mar 15MDT | 6:41 AM | 7:11 AM | 7:41 AM |
| Apr 1MDT | 6:08 AM | 6:38 AM | 7:08 AM |
| Apr 15MDT | 5:42 AM | 6:11 AM | 6:42 AM |
| May 1MDT | 5:15 AM | 5:42 AM | 6:15 AM |
| May 15MDT | 4:56 AM | 5:20 AM | 5:56 AM |
| Jun 1MDT | 4:40 AM | 5:03 AM | 5:40 AM |
| Jun 15MDT | 4:36 AM | 4:57 AM | 5:36 AM |
| Jul 1MDT | 4:41 AM | 5:02 AM | 5:41 AM |
| Jul 15MDT | 4:52 AM | 5:14 AM | 5:52 AM |
| Aug 1MDT | 5:10 AM | 5:35 AM | 6:10 AM |
| Aug 15MDT | 5:27 AM | 5:55 AM | 6:27 AM |
| Sep 1MDT | 5:49 AM | 6:18 AM | 6:49 AM |
| Sep 15MDT | 6:06 AM | 6:36 AM | 7:06 AM |
| Oct 1MDT | 6:27 AM | 6:57 AM | 7:27 AM |
| Oct 15MDT | 6:45 AM | 7:15 AM | 7:45 AM |
Lights and runways
As the FAA lists them. NOTAMs aren't included, so check current NOTAMs before you fly.
Runway 11/29
3,675 × 72 ft · Turf
Frequencies
Night at 3U9, in short
When can I log night time at 3U9?
From the end of evening civil twilight to the beginning of morning civil twilight, when the sun is 6° below the horizon (14 CFR 1.1). On the night of Nov 6, 2026, that was 5:38 PM to 6:46 AM MST.
When do landings at 3U9 count for night currency?
From one hour after sunset to one hour before sunrise. To carry passengers at night you need 3 takeoffs and 3 full-stop landings in that period within the last 90 days (14 CFR 61.57(b)). On the night of Nov 6, 2026, that was 6:07 PM to 6:18 AM MST.
When are position lights required at 3U9?
From sunset to sunrise (14 CFR 91.209(a)). On the night of Nov 6, 2026, that was 5:07 PM to 7:18 AM MST.
Nearby airports
- KBTM Bert Mooney Butte, MT · 22 nm
- KHLN Helena Regional Helena, MT · 24 nm
- 8U9 Canyon Ferry Townsend, MT · 25 nm
- 8U8 Townsend Townsend, MT · 27 nm
- 38S Deer Lodge-City-County Deer Lodge, MT · 29 nm
- 9S5 Three Forks Three Forks, MT · 30 nm
Times are worked out from the sun's position for a sea-level horizon, rounded to the minute. Airport data from the FAA NASR cycle of Oct 29, 2026.