Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for 3C 273: 11-13 (9), 11-12 (7), 11-11 (6), 11-10 (5), 11-09 (4) — by astronomy; check the weather when the night is within four days.

2029-10-15astronomy score per night — click a bar for that night2029-11-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-10-15 Mon	0	—	unknown	—	50.2° 12:15	9.83	65%	123.9°
2029-10-16 Tue	0	—	unknown	—	50.2° 12:10	9.88	74%	136.2°
2029-10-17 Wed	0	—	unknown	—	50.2° 12:05	9.92	82%	148.1°
2029-10-18 Thu	0	—	unknown	—	50.2° 12:00	9.96	89%	159.3°
2029-10-19 Fri	0	—	unknown	—	50.2° 11:55	10.0	94%	168.4°
2029-10-20 Sat	0	—	unknown	—	50.2° 11:50	10.05	98%	168.7°
2029-10-21 Sun	0	—	unknown	—	50.2° 11:45	10.09	100%	160.0°
2029-10-22 Mon	0	—	unknown	—	50.2° 11:45	10.13	100%	149.1°
2029-10-23 Tue	0	—	unknown	—	50.2° 11:40	10.17	98%	137.8°
2029-10-24 Wed	0	—	unknown	—	50.2° 11:35	10.21	94%	126.3°
2029-10-25 Thu	0	—	unknown	—	50.2° 11:30	10.25	89%	114.6°
2029-10-26 Fri	0	—	unknown	—	50.2° 11:30	10.29	83%	102.8°
2029-10-27 Sat	0	—	unknown	—	50.2° 10:25	10.32	75%	90.8°
2029-10-28 Sun	0	—	unknown	—	50.2° 10:20	10.36	66%	78.6°
2029-10-29 Mon	0	—	unknown	—	50.2° 10:15	10.4	56%	66.2°
2029-10-30 Tue	0	—	unknown	—	50.2° 10:10	10.44	45%	53.4°
2029-10-31 Wed	0	—	unknown	—	50.2° 10:10	10.48	35%	40.4°
2029-11-01 Thu	0	—	unknown	—	50.2° 10:05	10.51	25%	27.2°
2029-11-02 Fri	0	—	unknown	—	50.2° 10:00	10.55	15%	14.9°
2029-11-03 Sat	1	—	unknown	—	50.2° 09:55	10.58	8%	10.5°
2029-11-04 Sun	1	—	unknown	—	50.2° 09:50	10.62	3%	21.0°
2029-11-05 Mon	1	—	unknown	—	50.2° 09:50	10.65	0%	35.1°
2029-11-06 Tue	1	—	unknown	—	50.2° 09:45	10.69	1%	49.9°
2029-11-07 Wed	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:40	10.72	4%	64.7°
2029-11-08 Thu	3	—	unknown	05:50–06:05 (marginal, 0.25 h)	50.2° 09:35	10.75	11%	79.2°
2029-11-09 Fri	4	—	unknown	05:15–05:30 (marginal, 0.25 h)	50.2° 09:35	10.79	19%	93.4°
2029-11-10 Sat	5	—	unknown	05:40–06:05 (marginal, 0.42 h)	50.2° 09:30	10.82	28%	107.1°
2029-11-11 Sun	6	—	unknown	05:10–05:35 (marginal, 0.42 h)	50.2° 09:25	10.85	39%	120.2°
2029-11-12 Mon	7	—	unknown	05:05–06:05 (marginal, 1.0 h)	50.2° 09:20	10.88	49%	132.9°
2029-11-13 Tue	9	—	unknown	05:30–05:35 (good, 0.08 h)	50.2° 09:15	10.91	59%	145.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-10-15&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.