Computation method: All values computed using the Spencer (1971) solar declination formula and the standard hour-angle equation. Sunrise and sunset are defined as the moment when the centre of the sun’s disc is 0.8333° below the geometric horizon (accounting for atmospheric refraction ~0.5667° and the sun’s mean semi-diameter ~0.2667°). Times are rounded to the nearest minute.
Accuracy: The Spencer (1971) Fourier series
approximation has a declination RMS error of ~0.02°, but timing
errors can reach ±10–15 minutes near the solstices at NZ latitudes
due to the sensitivity of the hour-angle formula. Equinox-period
dates are more accurate (typically ±3–5 minutes). Cross-check:
Auckland winter solstice (21 Jun 2026) is computed here as 9h 38m;
the published almanac value is approximately 9h 27m (11-minute
discrepancy). For navigation-quality times, use
scripts/generate_almanac.py (requires Skyfield) which
achieves sub-minute accuracy using the JPL DE421 ephemeris. These
tables are adequate for recovery planning and scheduling
purposes.
Timezone: NZST = UTC+12 (standard time, April to September). NZDT = UTC+13 (daylight saving, last Sunday September to first Sunday April). For 2026: NZDT ends 5 April, NZDT resumes 27 September.
Reproduction: Any computer with Python 3 and
no external libraries can reproduce and extend these tables by
running scripts/generate_day_length.py.
Sunrise and Sunset Tables — 2026
Times given for the 1st and 15th of each month. All times in local NZ time (NZDT or NZST as noted).
Auckland (36.85°S)
| Date | Tz | Sunrise | Sunset | Day length |
|---|---|---|---|---|
| 01 Jan | NZDT | 06:05 | 20:43 | 14h 38m |
| 15 Jan | NZDT | 06:17 | 20:42 | 14h 25m |
| 01 Feb | NZDT | 06:36 | 20:33 | 13h 57m |
| 15 Feb | NZDT | 06:51 | 20:19 | 13h 28m |
| 01 Mar | NZDT | 07:06 | 20:02 | 12h 56m |
| 15 Mar | NZDT | 07:19 | 19:42 | 12h 23m |
| 01 Apr | NZDT | 07:34 | 19:17 | 11h 43m |
| 15 Apr | NZST | 06:46 | 17:57 | 11h 11m |
| 01 May | NZST | 06:59 | 17:37 | 10h 37m |
| 15 May | NZST | 07:11 | 17:23 | 10h 12m |
| 01 Jun | NZST | 07:24 | 17:13 | 9h 49m |
| 15 Jun | NZST | 07:31 | 17:10 | 9h 39m |
| 01 Jul | NZST | 07:35 | 17:14 | 9h 40m |
| 15 Jul | NZST | 07:31 | 17:22 | 9h 51m |
| 01 Aug | NZST | 07:20 | 17:35 | 10h 15m |
| 15 Aug | NZST | 07:06 | 17:46 | 10h 41m |
| 01 Sep | NZST | 06:43 | 18:00 | 11h 17m |
| 15 Sep | NZST | 06:22 | 18:10 | 11h 48m |
| 01 Oct | NZDT | 06:58 | 19:23 | 12h 26m |
| 15 Oct | NZDT | 06:37 | 19:36 | 12h 58m |
| 01 Nov | NZDT | 06:16 | 19:53 | 13h 36m |
| 15 Nov | NZDT | 06:04 | 20:08 | 14h 04m |
| 01 Dec | NZDT | 05:56 | 20:24 | 14h 28m |
| 15 Dec | NZDT | 05:56 | 20:36 | 14h 40m |
Wellington (41.29°S)
| Date | Tz | Sunrise | Sunset | Day length |
|---|---|---|---|---|
| 01 Jan | NZDT | 05:51 | 20:57 | 15h 06m |
| 15 Jan | NZDT | 06:04 | 20:55 | 14h 50m |
| 01 Feb | NZDT | 06:26 | 20:43 | 14h 17m |
| 15 Feb | NZDT | 06:44 | 20:26 | 13h 43m |
| 01 Mar | NZDT | 07:01 | 20:06 | 13h 05m |
| 15 Mar | NZDT | 07:18 | 19:44 | 12h 26m |
| 01 Apr | NZDT | 07:36 | 19:15 | 11h 39m |
| 15 Apr | NZST | 06:50 | 17:52 | 11h 02m |
| 01 May | NZST | 07:07 | 17:29 | 10h 22m |
| 15 May | NZST | 07:21 | 17:13 | 9h 52m |
| 01 Jun | NZST | 07:36 | 17:00 | 9h 24m |
| 15 Jun | NZST | 07:45 | 16:57 | 9h 13m |
| 01 Jul | NZST | 07:47 | 17:01 | 9h 14m |
| 15 Jul | NZST | 07:43 | 17:10 | 9h 27m |
| 01 Aug | NZST | 07:30 | 17:25 | 9h 55m |
| 15 Aug | NZST | 07:13 | 17:39 | 10h 26m |
| 01 Sep | NZST | 06:47 | 17:55 | 11h 08m |
| 15 Sep | NZST | 06:24 | 18:09 | 11h 45m |
| 01 Oct | NZDT | 06:56 | 19:25 | 12h 29m |
| 15 Oct | NZDT | 06:33 | 19:40 | 13h 07m |
| 01 Nov | NZDT | 06:08 | 20:01 | 13h 52m |
| 15 Nov | NZDT | 05:53 | 20:18 | 14h 25m |
| 01 Dec | NZDT | 05:43 | 20:37 | 14h 54m |
| 15 Dec | NZDT | 05:42 | 20:50 | 15h 08m |
Christchurch (43.53°S)
| Date | Tz | Sunrise | Sunset | Day length |
|---|---|---|---|---|
| 01 Jan | NZDT | 05:51 | 21:13 | 15h 22m |
| 15 Jan | NZDT | 06:06 | 21:10 | 15h 04m |
| 01 Feb | NZDT | 06:29 | 20:57 | 14h 28m |
| 15 Feb | NZDT | 06:48 | 20:39 | 13h 51m |
| 01 Mar | NZDT | 07:07 | 20:17 | 13h 10m |
| 15 Mar | NZDT | 07:25 | 19:53 | 12h 28m |
| 01 Apr | NZDT | 07:45 | 19:22 | 11h 37m |
| 15 Apr | NZST | 07:01 | 17:58 | 10h 56m |
| 01 May | NZST | 07:20 | 17:33 | 10h 13m |
| 15 May | NZST | 07:35 | 17:16 | 9h 40m |
| 01 Jun | NZST | 07:52 | 17:02 | 9h 11m |
| 15 Jun | NZST | 08:01 | 16:58 | 8h 58m |
| 01 Jul | NZST | 08:03 | 17:02 | 8h 59m |
| 15 Jul | NZST | 07:59 | 17:12 | 9h 13m |
| 01 Aug | NZST | 07:44 | 17:28 | 9h 44m |
| 15 Aug | NZST | 07:25 | 17:43 | 10h 18m |
| 01 Sep | NZST | 06:58 | 18:02 | 11h 04m |
| 15 Sep | NZST | 06:33 | 18:17 | 11h 44m |
| 01 Oct | NZDT | 07:03 | 19:34 | 12h 31m |
| 15 Oct | NZDT | 06:39 | 19:51 | 13h 12m |
| 01 Nov | NZDT | 06:13 | 20:14 | 14h 01m |
| 15 Nov | NZDT | 05:56 | 20:33 | 14h 37m |
| 01 Dec | NZDT | 05:45 | 20:53 | 15h 08m |
| 15 Dec | NZDT | 05:43 | 21:06 | 15h 23m |
Dunedin (45.87°S)
| Date | Tz | Sunrise | Sunset | Day length |
|---|---|---|---|---|
| 01 Jan | NZDT | 05:51 | 21:31 | 15h 40m |
| 15 Jan | NZDT | 06:06 | 21:27 | 15h 21m |
| 01 Feb | NZDT | 06:31 | 21:12 | 14h 41m |
| 15 Feb | NZDT | 06:52 | 20:52 | 14h 00m |
| 01 Mar | NZDT | 07:13 | 20:29 | 13h 15m |
| 15 Mar | NZDT | 07:33 | 20:02 | 12h 30m |
| 01 Apr | NZDT | 07:55 | 19:30 | 11h 35m |
| 15 Apr | NZST | 07:13 | 18:04 | 10h 51m |
| 01 May | NZST | 07:33 | 17:37 | 10h 04m |
| 15 May | NZST | 07:50 | 17:18 | 9h 28m |
| 01 Jun | NZST | 08:08 | 17:03 | 8h 55m |
| 15 Jun | NZST | 08:18 | 16:58 | 8h 41m |
| 01 Jul | NZST | 08:20 | 17:02 | 8h 42m |
| 15 Jul | NZST | 08:15 | 17:13 | 8h 58m |
| 01 Aug | NZST | 07:59 | 17:30 | 9h 32m |
| 15 Aug | NZST | 07:39 | 17:47 | 10h 08m |
| 01 Sep | NZST | 07:09 | 18:08 | 10h 58m |
| 15 Sep | NZST | 06:42 | 18:24 | 11h 42m |
| 01 Oct | NZDT | 07:11 | 19:44 | 12h 33m |
| 15 Oct | NZDT | 06:44 | 20:03 | 13h 18m |
| 01 Nov | NZDT | 06:16 | 20:27 | 14h 11m |
| 15 Nov | NZDT | 05:58 | 20:48 | 14h 50m |
| 01 Dec | NZDT | 05:45 | 21:10 | 15h 25m |
| 15 Dec | NZDT | 05:42 | 21:24 | 15h 42m |
Invercargill (46.41°S)
| Date | Tz | Sunrise | Sunset | Day length |
|---|---|---|---|---|
| 01 Jan | NZDT | 05:57 | 21:42 | 15h 44m |
| 15 Jan | NZDT | 06:13 | 21:37 | 15h 25m |
| 01 Feb | NZDT | 06:38 | 21:22 | 14h 44m |
| 15 Feb | NZDT | 07:00 | 21:02 | 14h 02m |
| 01 Mar | NZDT | 07:21 | 20:38 | 13h 17m |
| 15 Mar | NZDT | 07:41 | 20:11 | 12h 30m |
| 01 Apr | NZDT | 08:04 | 19:38 | 11h 34m |
| 15 Apr | NZST | 07:22 | 18:11 | 10h 49m |
| 01 May | NZST | 07:43 | 17:44 | 10h 01m |
| 15 May | NZST | 08:00 | 17:25 | 9h 25m |
| 01 Jun | NZST | 08:18 | 17:10 | 8h 51m |
| 15 Jun | NZST | 08:28 | 17:05 | 8h 37m |
| 01 Jul | NZST | 08:31 | 17:09 | 8h 38m |
| 15 Jul | NZST | 08:25 | 17:19 | 8h 54m |
| 01 Aug | NZST | 08:09 | 17:38 | 9h 29m |
| 15 Aug | NZST | 07:48 | 17:54 | 10h 06m |
| 01 Sep | NZST | 07:18 | 18:15 | 10h 57m |
| 15 Sep | NZST | 06:51 | 18:33 | 11h 42m |
| 01 Oct | NZDT | 07:19 | 19:53 | 12h 34m |
| 15 Oct | NZDT | 06:52 | 20:12 | 13h 20m |
| 01 Nov | NZDT | 06:23 | 20:37 | 14h 14m |
| 15 Nov | NZDT | 06:05 | 20:58 | 14h 54m |
| 01 Dec | NZDT | 05:51 | 21:20 | 15h 29m |
| 15 Dec | NZDT | 05:49 | 21:35 | 15h 46m |
Twilight Tables — Wellington 41°S — 2026
Twilight times for the 1st of each month. Twilight categories:
- Civil twilight (sun 6° below horizon): sufficient illumination for most outdoor activities without artificial light. Horizon clearly visible.
- Nautical twilight (sun 12° below horizon): sea horizon visible; stars bright enough for sextant observations.
- Astronomical twilight (sun 18° below horizon): sky dark enough for faint telescopic objects. Below this threshold, night is fully dark.
Wellington (41.29°S) — Twilight Times (1st of each month)
All times in local NZ time. ‘Begin’ = twilight starts (morning, before sunrise); ‘End’ = twilight ends (evening, after sunset).
Civil Twilight (sun 6° below horizon)
| Date | Tz | Morning begin | Sunrise | Sunset | Evening end |
|---|---|---|---|---|---|
| 01 Jan | NZDT | 05:17 | 05:51 | 20:57 | 21:30 |
| 01 Feb | NZDT | 05:55 | 06:26 | 20:43 | 21:13 |
| 01 Mar | NZDT | 06:33 | 07:01 | 20:06 | 20:35 |
| 01 Apr | NZDT | 07:08 | 07:36 | 19:15 | 19:42 |
| 01 May | NZST | 06:38 | 07:07 | 17:29 | 17:58 |
| 01 Jun | NZST | 07:05 | 07:36 | 17:00 | 17:31 |
| 01 Jul | NZST | 07:16 | 07:47 | 17:01 | 17:32 |
| 01 Aug | NZST | 07:00 | 07:30 | 17:25 | 17:55 |
| 01 Sep | NZST | 06:19 | 06:47 | 17:55 | 18:23 |
| 01 Oct | NZDT | 06:28 | 06:56 | 19:25 | 19:53 |
| 01 Nov | NZDT | 05:39 | 06:08 | 20:01 | 20:30 |
| 01 Dec | NZDT | 05:10 | 05:43 | 20:37 | 21:10 |
Nautical Twilight (sun 12° below horizon)
| Date | Tz | Morning begin | Sunrise | Sunset | Evening end |
|---|---|---|---|---|---|
| 01 Jan | NZDT | 04:34 | 05:51 | 20:57 | 22:13 |
| 01 Feb | NZDT | 05:17 | 06:26 | 20:43 | 21:51 |
| 01 Mar | NZDT | 05:59 | 07:01 | 20:06 | 21:08 |
| 01 Apr | NZDT | 06:36 | 07:36 | 19:15 | 20:14 |
| 01 May | NZST | 06:06 | 07:07 | 17:29 | 18:30 |
| 01 Jun | NZST | 06:31 | 07:36 | 17:00 | 18:06 |
| 01 Jul | NZST | 06:42 | 07:47 | 17:01 | 18:07 |
| 01 Aug | NZST | 06:27 | 07:30 | 17:25 | 18:28 |
| 01 Sep | NZST | 05:47 | 06:47 | 17:55 | 18:55 |
| 01 Oct | NZDT | 05:56 | 06:56 | 19:25 | 20:25 |
| 01 Nov | NZDT | 05:03 | 06:08 | 20:01 | 21:06 |
| 01 Dec | NZDT | 04:29 | 05:43 | 20:37 | 21:51 |
Astronomical Twilight (sun 18° below horizon)
| Date | Tz | Morning begin | Sunrise | Sunset | Evening end |
|---|---|---|---|---|---|
| 01 Jan | NZDT | 03:43 | 05:51 | 20:57 | 23:04 |
| 01 Feb | NZDT | 04:35 | 06:26 | 20:43 | 22:33 |
| 01 Mar | NZDT | 05:24 | 07:01 | 20:06 | 21:44 |
| 01 Apr | NZDT | 06:04 | 07:36 | 19:15 | 20:47 |
| 01 May | NZST | 05:33 | 07:07 | 17:29 | 19:02 |
| 01 Jun | NZST | 05:58 | 07:36 | 17:00 | 18:39 |
| 01 Jul | NZST | 06:08 | 07:47 | 17:01 | 18:41 |
| 01 Aug | NZST | 05:54 | 07:30 | 17:25 | 19:00 |
| 01 Sep | NZST | 05:15 | 06:47 | 17:55 | 19:27 |
| 01 Oct | NZDT | 05:22 | 06:56 | 19:25 | 20:59 |
| 01 Nov | NZDT | 04:23 | 06:08 | 20:01 | 21:46 |
| 01 Dec | NZDT | 03:41 | 05:43 | 20:37 | 22:40 |
Solstice and Equinox Dates — 2026
Approximate dates and times (UTC) computed from the Meeus (1998) low-precision formula. Accuracy is typically within 15 minutes.
| Event | UTC Date/Time | NZ Local | Notes |
|---|---|---|---|
| March Equinox | 20 Mar 2026 14:28 | 21 Mar 03:28 NZDT | Autumnal equinox in Southern Hemisphere (day = night) |
| June Solstice | 21 Jun 2026 08:45 | 21 Jun 20:45 NZST | Winter solstice in Southern Hemisphere (shortest day) |
| September Equinox | 23 Sep 2026 00:14 | 23 Sep 12:14 NZST | Vernal equinox in Southern Hemisphere (day = night) |
| December Solstice | 21 Dec 2026 20:22 | 22 Dec 09:22 NZDT | Summer solstice in Southern Hemisphere (longest day) |
Note on Southern Hemisphere seasons: The June solstice is mid-winter in New Zealand (shortest day), and the December solstice is mid-summer (longest day). This is the reverse of Northern Hemisphere conventions found in most international reference works.
Day Length Summary — 2026
Minimum and maximum day lengths computed by scanning all 365 days of 2026. The extreme values occur on or near the solstices.
| City | Latitude | Shortest day | Date | Longest day | Date |
|---|---|---|---|---|---|
| Auckland | 36.85°S | 9h 38m | 22 Jun | 14h 41m | 22 Dec |
| Wellington | 41.29°S | 9h 11m | 22 Jun | 15h 09m | 22 Dec |
| Christchurch | 43.53°S | 8h 56m | 22 Jun | 15h 25m | 22 Dec |
| Dunedin | 45.87°S | 8h 39m | 22 Jun | 15h 44m | 22 Dec |
| Invercargill | 46.41°S | 8h 35m | 22 Jun | 15h 49m | 22 Dec |
Generated by scripts/generate_day_length.py
using Python standard library (math, datetime). Solar declination:
Spencer (1971) Fourier series. Hour-angle equation: standard
spherical astronomy formula.