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: 02-22 (93), 02-23 (93), 02-24 (93), 02-25 (93), 02-26 (93) — by astronomy; check the weather when the night is within four days.

2036-02-22astronomy score per night — click a bar for that night2036-03-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-02-22 Fri	93	—	unknown	22:55–05:35 (good, 6.67 h)	50.2° 02:40	9.97	16%	101.0°
2036-02-23 Sat	93	—	unknown	22:50–05:35 (good, 6.75 h)	50.2° 02:40	9.93	10%	112.8°
2036-02-24 Sun	93	—	unknown	22:45–05:35 (good, 6.83 h)	50.2° 02:35	9.89	5%	124.7°
2036-02-25 Mon	93	—	unknown	22:45–05:30 (good, 6.75 h)	50.2° 02:30	9.84	2%	136.7°
2036-02-26 Tue	93	—	unknown	22:40–05:30 (good, 6.83 h)	50.2° 02:25	9.8	0%	148.8°
2036-02-27 Wed	93	—	unknown	22:35–05:30 (good, 6.92 h)	50.2° 02:20	9.76	0%	161.1°
2036-02-28 Thu	93	—	unknown	22:30–05:25 (good, 6.92 h)	50.2° 02:20	9.71	3%	173.5°
2036-02-29 Fri	93	—	unknown	22:30–05:25 (good, 6.92 h)	50.2° 02:15	9.67	7%	173.6°
2036-03-01 Sat	93	—	unknown	22:25–05:25 (good, 7.0 h)	50.2° 02:10	9.62	14%	160.8°
2036-03-02 Sun	93	—	unknown	22:20–05:20 (good, 7.0 h)	50.2° 02:05	9.57	22%	147.8°
2036-03-03 Mon	93	—	unknown	22:20–05:20 (good, 7.0 h)	50.2° 02:05	9.53	31%	134.5°
2036-03-04 Tue	93	—	unknown	22:15–05:20 (good, 7.08 h)	50.2° 02:00	9.48	42%	121.0°
2036-03-05 Wed	93	—	unknown	22:20–05:20 (good, 7.0 h)	50.2° 01:55	9.44	53%	107.2°
2036-03-06 Thu	92	—	unknown	22:25–05:15 (good, 6.83 h)	50.2° 01:50	9.39	64%	93.1°
2036-03-07 Fri	88	—	unknown	23:15–05:15 (good, 6.0 h)	50.2° 01:45	9.34	75%	78.7°
2036-03-08 Sat	82	—	unknown	01:40–05:15 (good, 3.58 h)	50.2° 01:45	9.29	84%	64.2°
2036-03-09 Sun	48	—	unknown	22:05–05:10 (marginal, 7.08 h)	50.2° 01:40	9.24	92%	49.5°
2036-03-10 Mon	29	—	unknown	00:45–05:10 (marginal, 4.42 h)	50.2° 01:35	9.2	97%	34.7°
2036-03-11 Tue	21	—	unknown	02:30–05:05 (marginal, 2.58 h)	50.2° 01:30	9.15	100%	20.1°
2036-03-12 Wed	20	—	unknown	03:00–05:05 (marginal, 2.08 h)	50.2° 01:25	9.1	100%	5.8°
2036-03-13 Thu	24	—	unknown	21:40–05:00 (marginal, 7.33 h)	50.2° 01:25	9.05	97%	8.7°
2036-03-14 Fri	35	—	unknown	21:15–05:00 (marginal, 7.75 h)	50.2° 01:20	9.0	92%	22.3°
2036-03-15 Sat	81	—	unknown	21:30–22:10 (good, 0.67 h)	50.2° 01:15	8.95	85%	35.7°
2036-03-16 Sun	87	—	unknown	21:25–01:45 (good, 4.33 h)	50.2° 01:10	8.9	77%	48.6°
2036-03-17 Mon	92	—	unknown	21:20–03:50 (good, 6.5 h)	50.2° 01:10	8.85	68%	61.2°
2036-03-18 Tue	93	—	unknown	21:15–04:35 (good, 7.33 h)	50.2° 01:05	8.8	58%	73.4°
2036-03-19 Wed	93	—	unknown	21:15–04:40 (good, 7.42 h)	50.2° 01:00	8.74	48%	85.4°
2036-03-20 Thu	93	—	unknown	21:10–04:40 (good, 7.5 h)	50.2° 00:55	8.69	39%	97.3°
2036-03-21 Fri	93	—	unknown	21:05–04:40 (good, 7.58 h)	50.2° 00:50	8.64	30%	109.1°
2036-03-22 Sat	93	—	unknown	21:00–04:40 (good, 7.67 h)	50.2° 00:50	8.59	22%	121.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-02-22&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.