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: 04-02 (93), 04-03 (93), 04-04 (93), 04-05 (93), 04-06 (93) — by astronomy; check the weather when the night is within four days.

2029-03-22astronomy score per night — click a bar for that night2029-04-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-03-22 Thu	92	—	unknown	21:15–04:40 (good, 7.42 h)	50.2° 00:50	8.6	46%	97.6°
2029-03-23 Fri	89	—	unknown	21:20–04:35 (good, 7.25 h)	50.2° 00:45	8.55	56%	85.0°
2029-03-24 Sat	85	—	unknown	22:20–05:35 (good, 6.25 h)	50.2° 00:40	8.5	67%	71.9°
2029-03-25 Sun	81	—	unknown	01:35–05:30 (good, 3.92 h)	50.2° 01:35	8.45	77%	58.4°
2029-03-26 Mon	62	—	unknown	05:15–05:25 (good, 0.17 h)	50.2° 01:35	8.39	86%	44.5°
2029-03-27 Tue	33	—	unknown	23:50–05:35 (marginal, 5.75 h)	50.2° 01:30	8.34	93%	30.4°
2029-03-28 Wed	27	—	unknown	00:35–05:25 (marginal, 4.83 h)	50.2° 01:25	8.28	98%	17.0°
2029-03-29 Thu	25	—	unknown	21:45–05:10 (marginal, 7.42 h)	50.2° 01:20	8.23	100%	9.8°
2029-03-30 Fri	32	—	unknown	21:20–05:00 (marginal, 7.67 h)	50.2° 01:15	8.18	99%	19.2°
2029-03-31 Sat	76	—	unknown	21:25–22:05 (good, 0.67 h)	50.2° 01:15	8.12	95%	33.1°
2029-04-01 Sun	88	—	unknown	21:25–00:40 (good, 3.25 h)	50.2° 01:10	8.07	88%	47.4°
2029-04-02 Mon	93	—	unknown	21:25–03:25 (good, 6.0 h)	50.2° 01:05	8.01	80%	61.6°
2029-04-03 Tue	93	—	unknown	21:30–04:30 (good, 7.0 h)	50.2° 01:00	7.96	70%	75.4°
2029-04-04 Wed	93	—	unknown	21:30–04:35 (good, 7.08 h)	50.2° 01:00	7.9	59%	88.7°
2029-04-05 Thu	93	—	unknown	21:30–04:40 (good, 7.17 h)	50.2° 00:55	7.85	49%	101.7°
2029-04-06 Fri	93	—	unknown	21:30–04:40 (good, 7.17 h)	50.2° 00:50	7.79	39%	114.2°
2029-04-07 Sat	93	—	unknown	21:35–04:35 (good, 7.0 h)	50.2° 00:45	7.73	29%	126.4°
2029-04-08 Sun	93	—	unknown	21:35–04:35 (good, 7.0 h)	50.2° 00:40	7.68	21%	138.3°
2029-04-09 Mon	93	—	unknown	21:35–04:30 (good, 6.92 h)	50.2° 00:40	7.62	14%	149.8°
2029-04-10 Tue	93	—	unknown	21:40–04:25 (good, 6.75 h)	50.2° 00:35	7.56	8%	160.6°
2029-04-11 Wed	93	—	unknown	21:40–04:20 (good, 6.67 h)	50.2° 00:30	7.51	4%	169.0°
2029-04-12 Thu	93	—	unknown	21:40–04:20 (good, 6.67 h)	50.2° 00:25	7.45	1%	168.1°
2029-04-13 Fri	93	—	unknown	21:40–04:15 (good, 6.58 h)	50.2° 00:20	7.39	0%	159.0°
2029-04-14 Sat	93	—	unknown	21:45–04:10 (good, 6.42 h)	50.2° 00:20	7.33	1%	148.1°
2029-04-15 Sun	93	—	unknown	21:45–04:05 (good, 6.33 h)	50.2° 00:15	7.28	4%	136.7°
2029-04-16 Mon	93	—	unknown	21:45–04:00 (good, 6.25 h)	50.2° 00:10	7.22	8%	125.0°
2029-04-17 Tue	93	—	unknown	21:50–04:00 (good, 6.17 h)	50.2° 00:05	7.16	14%	113.0°
2029-04-18 Wed	93	—	unknown	21:50–03:55 (good, 6.08 h)	50.2° 00:05	7.1	22%	100.9°
2029-04-19 Thu	90	—	unknown	21:50–03:50 (good, 6.0 h)	50.2° 00:00	7.05	31%	88.5°
2029-04-20 Fri	87	—	unknown	21:50–03:45 (good, 5.92 h)	50.2° 23:55	6.99	40%	75.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-03-22&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.