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: 11-15 (7), 11-14 (5), 11-13 (4), 11-11 (3), 11-12 (3) — by astronomy; check the weather when the night is within four days.

2033-10-17astronomy score per night — click a bar for that night2033-11-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-10-17 Mon	0	—	unknown	—	50.2° 12:05	9.92	24%	40.5°
2033-10-18 Tue	0	—	unknown	—	50.2° 12:00	9.96	16%	28.6°
2033-10-19 Wed	0	—	unknown	—	50.2° 11:55	10.0	10%	17.1°
2033-10-20 Thu	0	—	unknown	—	50.2° 11:50	10.05	5%	6.9°
2033-10-21 Fri	0	—	unknown	—	50.2° 11:45	10.09	2%	9.2°
2033-10-22 Sat	0	—	unknown	—	50.2° 11:45	10.13	0%	20.0°
2033-10-23 Sun	0	—	unknown	—	50.2° 11:40	10.17	0%	31.6°
2033-10-24 Mon	0	—	unknown	—	50.2° 11:35	10.21	2%	43.4°
2033-10-25 Tue	0	—	unknown	—	50.2° 11:30	10.25	6%	55.3°
2033-10-26 Wed	0	—	unknown	—	50.2° 11:30	10.29	12%	67.4°
2033-10-27 Thu	0	—	unknown	—	50.2° 11:25	10.33	19%	79.6°
2033-10-28 Fri	0	—	unknown	—	50.2° 11:20	10.36	27%	92.1°
2033-10-29 Sat	0	—	unknown	—	50.2° 10:15	10.4	37%	104.8°
2033-10-30 Sun	0	—	unknown	—	50.2° 10:10	10.44	47%	117.8°
2033-10-31 Mon	0	—	unknown	—	50.2° 10:10	10.48	58%	131.2°
2033-11-01 Tue	0	—	unknown	—	50.2° 10:05	10.51	69%	144.9°
2033-11-02 Wed	0	—	unknown	—	50.2° 10:00	10.55	79%	158.9°
2033-11-03 Thu	1	—	unknown	—	50.2° 09:55	10.58	88%	172.1°
2033-11-04 Fri	1	—	unknown	—	50.2° 09:50	10.62	94%	169.4°
2033-11-05 Sat	1	—	unknown	—	50.2° 09:50	10.65	99%	155.2°
2033-11-06 Sun	1	—	unknown	—	50.2° 09:45	10.69	100%	140.2°
2033-11-07 Mon	2	—	unknown	05:25–05:30 (marginal, 0.08 h)	50.2° 09:40	10.72	98%	125.3°
2033-11-08 Tue	2	—	unknown	05:20–05:30 (marginal, 0.17 h)	50.2° 09:35	10.75	94%	110.7°
2033-11-09 Wed	2	—	unknown	05:20–05:30 (marginal, 0.17 h)	50.2° 09:35	10.79	87%	96.4°
2033-11-10 Thu	2	—	unknown	05:20–05:30 (marginal, 0.17 h)	50.2° 09:30	10.82	79%	82.6°
2033-11-11 Fri	3	—	unknown	05:15–05:35 (marginal, 0.33 h)	50.2° 09:25	10.85	69%	69.3°
2033-11-12 Sat	3	—	unknown	05:15–05:35 (marginal, 0.33 h)	50.2° 09:20	10.88	59%	56.4°
2033-11-13 Sun	4	—	unknown	05:05–05:35 (marginal, 0.5 h)	50.2° 09:15	10.91	49%	43.9°
2033-11-14 Mon	5	—	unknown	05:00–05:35 (marginal, 0.58 h)	50.2° 09:15	10.94	40%	31.8°
2033-11-15 Tue	7	—	unknown	04:55–05:35 (marginal, 0.67 h)	50.2° 09:10	10.97	30%	20.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-10-17&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.