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: 07-13 (2), 07-14 (1), 07-15 (1), 07-16 (1), 07-17 (1) — by astronomy; check the weather when the night is within four days.

2036-07-13astronomy score per night — click a bar for that night2036-08-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-07-13 Sun	2	—	unknown	—	50.2° 18:25	4.94	75%	165.7°
2036-07-14 Mon	1	—	unknown	—	50.2° 18:20	4.98	66%	177.7°
2036-07-15 Tue	1	—	unknown	—	50.2° 18:15	5.02	57%	169.8°
2036-07-16 Wed	1	—	unknown	—	50.2° 18:10	5.07	47%	157.1°
2036-07-17 Thu	1	—	unknown	—	50.2° 18:10	5.11	36%	144.1°
2036-07-18 Fri	1	—	unknown	—	50.2° 18:05	5.16	26%	130.7°
2036-07-19 Sat	1	—	unknown	—	50.2° 18:00	5.2	17%	116.7°
2036-07-20 Sun	1	—	unknown	—	50.2° 17:55	5.25	9%	102.3°
2036-07-21 Mon	0	—	unknown	—	50.2° 17:50	5.3	3%	87.5°
2036-07-22 Tue	0	—	unknown	—	50.2° 17:50	5.35	0%	72.5°
2036-07-23 Wed	0	—	unknown	—	50.2° 17:45	5.4	0%	57.2°
2036-07-24 Thu	0	—	unknown	—	50.2° 17:40	5.45	3%	42.0°
2036-07-25 Fri	0	—	unknown	—	50.2° 17:35	5.5	9%	27.1°
2036-07-26 Sat	0	—	unknown	—	50.2° 17:35	5.56	17%	12.4°
2036-07-27 Sun	0	—	unknown	—	50.2° 17:30	5.61	27%	2.1°
2036-07-28 Mon	0	—	unknown	—	50.2° 17:25	5.66	37%	15.7°
2036-07-29 Tue	0	—	unknown	—	50.2° 17:20	5.72	48%	29.1°
2036-07-30 Wed	0	—	unknown	—	50.2° 17:15	5.77	58%	42.1°
2036-07-31 Thu	0	—	unknown	—	50.2° 17:15	5.82	68%	54.7°
2036-08-01 Fri	0	—	unknown	—	50.2° 17:10	5.88	77%	67.1°
2036-08-02 Sat	0	—	unknown	—	50.2° 17:05	5.94	85%	79.3°
2036-08-03 Sun	0	—	unknown	—	50.2° 17:00	5.99	91%	91.3°
2036-08-04 Mon	0	—	unknown	—	50.2° 16:55	6.05	96%	103.3°
2036-08-05 Tue	0	—	unknown	—	50.2° 16:55	6.1	99%	115.1°
2036-08-06 Wed	0	—	unknown	—	50.2° 16:50	6.16	100%	127.0°
2036-08-07 Thu	0	—	unknown	—	50.2° 16:45	6.22	99%	138.8°
2036-08-08 Fri	0	—	unknown	—	50.2° 16:40	6.27	97%	150.7°
2036-08-09 Sat	0	—	unknown	—	50.2° 16:35	6.33	93%	162.6°
2036-08-10 Sun	0	—	unknown	—	50.2° 16:35	6.39	87%	174.7°
2036-08-11 Mon	0	—	unknown	—	50.2° 16:30	6.45	80%	173.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-07-13&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.