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: 03-06 (93), 03-07 (93), 03-08 (93), 03-09 (93), 03-10 (93) — by astronomy; check the weather when the night is within four days.

2029-02-27astronomy score per night — click a bar for that night2029-03-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-02-27 Tue	31	—	unknown	00:45–05:30 (marginal, 4.75 h)	50.2° 02:20	9.72	99%	38.0°
2029-02-28 Wed	23	—	unknown	02:15–05:25 (marginal, 3.17 h)	50.2° 02:15	9.68	100%	23.9°
2029-03-01 Thu	25	—	unknown	22:45–05:25 (marginal, 6.67 h)	50.2° 02:10	9.63	98%	11.9°
2029-03-02 Fri	31	—	unknown	22:15–05:25 (marginal, 7.17 h)	50.2° 02:05	9.59	92%	12.8°
2029-03-03 Sat	52	—	unknown	21:50–05:20 (marginal, 7.5 h)	50.2° 02:05	9.54	85%	25.1°
2029-03-04 Sun	85	—	unknown	22:15–01:20 (good, 3.08 h)	50.2° 02:00	9.5	76%	38.9°
2029-03-05 Mon	91	—	unknown	22:10–04:35 (good, 6.42 h)	50.2° 01:55	9.45	65%	52.7°
2029-03-06 Tue	93	—	unknown	22:05–05:15 (good, 7.17 h)	50.2° 01:50	9.4	54%	66.2°
2029-03-07 Wed	93	—	unknown	22:00–05:15 (good, 7.25 h)	50.2° 01:50	9.35	44%	79.5°
2029-03-08 Thu	93	—	unknown	21:55–05:15 (good, 7.33 h)	50.2° 01:45	9.31	33%	92.3°
2029-03-09 Fri	93	—	unknown	21:55–05:10 (good, 7.25 h)	50.2° 01:40	9.26	24%	104.9°
2029-03-10 Sat	93	—	unknown	21:50–05:10 (good, 7.33 h)	50.2° 01:35	9.21	16%	117.3°
2029-03-11 Sun	93	—	unknown	21:45–05:10 (good, 7.42 h)	50.2° 01:30	9.16	10%	129.4°
2029-03-12 Mon	93	—	unknown	21:40–05:05 (good, 7.42 h)	50.2° 01:30	9.11	5%	141.2°
2029-03-13 Tue	93	—	unknown	21:35–05:05 (good, 7.5 h)	50.2° 01:25	9.06	2%	152.6°
2029-03-14 Wed	93	—	unknown	21:35–05:05 (good, 7.5 h)	50.2° 01:20	9.01	0%	163.2°
2029-03-15 Thu	93	—	unknown	21:30–05:00 (good, 7.5 h)	50.2° 01:15	8.96	1%	170.0°
2029-03-16 Fri	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.2° 01:10	8.91	3%	166.1°
2029-03-17 Sat	93	—	unknown	21:20–04:55 (good, 7.58 h)	50.2° 01:10	8.86	7%	156.3°
2029-03-18 Sun	93	—	unknown	21:20–04:55 (good, 7.58 h)	50.2° 01:05	8.81	12%	145.2°
2029-03-19 Mon	93	—	unknown	21:15–04:55 (good, 7.67 h)	50.2° 01:00	8.76	19%	133.7°
2029-03-20 Tue	93	—	unknown	21:10–04:50 (good, 7.67 h)	50.2° 00:55	8.71	27%	122.0°
2029-03-21 Wed	93	—	unknown	21:10–04:45 (good, 7.58 h)	50.2° 00:55	8.66	36%	109.9°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-02-27&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.