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 HD 189733: 03-03 (16), 03-02 (15), 02-24 (14), 02-25 (14), 02-26 (14) — by astronomy; check the weather when the night is within four days.

2043-02-02astronomy score per night — click a bar for that night2043-03-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-02-02 Mon	1	—	unknown	—	71.1° 11:30	10.73	43%	82.4°
2043-02-03 Tue	2	—	unknown	05:55–06:00 (marginal, 0.08 h)	71.1° 11:25	10.69	34%	74.4°
2043-02-04 Wed	2	—	unknown	—	71.1° 11:20	10.66	25%	66.7°
2043-02-05 Thu	2	—	unknown	06:20–06:30 (marginal, 0.17 h)	71.1° 11:20	10.63	17%	59.5°
2043-02-06 Fri	3	—	unknown	05:45–05:55 (marginal, 0.17 h)	71.1° 11:15	10.59	10%	53.3°
2043-02-07 Sat	4	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:10	10.55	5%	48.8°
2043-02-08 Sun	4	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:05	10.52	1%	46.7°
2043-02-09 Mon	5	—	unknown	06:00–06:25 (marginal, 0.42 h)	71.1° 11:00	10.48	0%	47.5°
2043-02-10 Tue	6	—	unknown	05:55–06:25 (marginal, 0.5 h)	71.1° 11:00	10.44	2%	51.3°
2043-02-11 Wed	6	—	unknown	05:25–05:50 (marginal, 0.42 h)	71.1° 10:55	10.41	5%	57.6°
2043-02-12 Thu	7	—	unknown	05:20–06:20 (marginal, 1.0 h)	71.1° 10:50	10.37	12%	65.6°
2043-02-13 Fri	7	—	unknown	05:20–06:20 (marginal, 1.0 h)	71.1° 10:45	10.33	20%	74.6°
2043-02-14 Sat	8	—	unknown	05:40–05:45 (good, 0.08 h)	71.1° 10:45	10.29	30%	84.3°
2043-02-15 Sun	9	—	unknown	05:35–05:45 (good, 0.17 h)	71.1° 10:40	10.25	41%	94.0°
2043-02-16 Mon	10	—	unknown	05:35–05:45 (good, 0.17 h)	71.1° 10:35	10.21	53%	103.6°
2043-02-17 Tue	11	—	unknown	05:30–05:40 (good, 0.17 h)	71.1° 10:30	10.17	64%	112.5°
2043-02-18 Wed	11	—	unknown	05:25–05:40 (good, 0.25 h)	71.1° 10:25	10.13	74%	120.5°
2043-02-19 Thu	12	—	unknown	05:20–05:40 (good, 0.33 h)	71.1° 10:25	10.09	83%	127.1°
2043-02-20 Fri	12	—	unknown	05:25–05:40 (good, 0.25 h)	71.1° 10:20	10.05	90%	131.5°
2043-02-21 Sat	12	—	unknown	05:20–05:35 (good, 0.25 h)	71.1° 10:15	10.0	96%	133.4°
2043-02-22 Sun	12	—	unknown	05:20–05:35 (good, 0.25 h)	71.1° 10:10	9.96	99%	132.4°
2043-02-23 Mon	13	—	unknown	05:15–05:35 (good, 0.33 h)	71.1° 10:05	9.92	100%	128.9°
2043-02-24 Tue	14	—	unknown	05:15–05:35 (good, 0.33 h)	71.1° 10:05	9.88	99%	123.4°
2043-02-25 Wed	14	—	unknown	05:10–05:30 (good, 0.33 h)	71.1° 10:00	9.83	96%	116.8°
2043-02-26 Thu	14	—	unknown	05:10–05:30 (good, 0.33 h)	71.1° 09:55	9.79	91%	109.3°
2043-02-27 Fri	13	—	unknown	05:10–05:30 (good, 0.33 h)	71.1° 09:50	9.74	85%	101.4°
2043-02-28 Sat	13	—	unknown	05:05–05:25 (good, 0.33 h)	71.1° 09:50	9.7	78%	93.3°
2043-03-01 Sun	13	—	unknown	05:05–05:25 (good, 0.33 h)	71.1° 09:45	9.65	70%	85.2°
2043-03-02 Mon	15	—	unknown	05:00–05:25 (good, 0.42 h)	71.1° 09:40	9.61	60%	77.2°
2043-03-03 Tue	16	—	unknown	04:50–05:20 (good, 0.5 h)	71.1° 09:35	9.56	51%	69.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-02-02&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.