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 Seven Sisters: 02-23 (88), 02-24 (88), 02-25 (87), 02-22 (86), 02-26 (83) — by astronomy; check the weather when the night is within four days.

2046-02-13astronomy score per night — click a bar for that night2046-03-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-02-13 Tue	50	—	unknown	19:30–22:55 (good, 3.42 h)	72.6° 18:35	10.32	48%	6.8°
2046-02-14 Wed	36	—	unknown	19:30–00:00 (marginal, 4.5 h)	72.6° 18:30	10.28	58%	6.2°
2046-02-15 Thu	24	—	unknown	19:30–23:45 (marginal, 4.25 h)	72.6° 18:25	10.24	68%	19.3°
2046-02-16 Fri	18	—	unknown	19:30–23:25 (marginal, 3.92 h)	72.6° 18:25	10.2	78%	33.0°
2046-02-17 Sat	20	—	unknown	19:30–23:20 (marginal, 3.83 h)	72.6° 18:20	10.16	87%	47.2°
2046-02-18 Sun	27	—	unknown	19:35–23:25 (marginal, 3.83 h)	72.6° 18:15	10.12	94%	61.9°
2046-02-19 Mon	38	—	unknown	19:35–20:30 (good, 0.92 h)	72.6° 18:10	10.08	98%	76.9°
2046-02-20 Tue	53	—	unknown	19:35–22:00 (good, 2.42 h)	72.6° 18:05	10.03	100%	92.1°
2046-02-21 Wed	68	—	unknown	19:35–22:55 (good, 3.33 h)	72.6° 18:05	9.99	98%	107.4°
2046-02-22 Thu	86	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 18:00	9.95	94%	122.6°
2046-02-23 Fri	88	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 17:55	9.91	87%	137.5°
2046-02-24 Sat	88	—	unknown	19:40–22:55 (good, 3.25 h)	72.6° 17:50	9.86	78%	152.0°
2046-02-25 Sun	87	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 17:50	9.82	68%	166.0°
2046-02-26 Mon	83	—	unknown	19:45–22:55 (good, 3.17 h)	72.6° 17:45	9.77	58%	179.0°
2046-02-27 Tue	82	—	unknown	19:45–22:50 (good, 3.08 h)	72.6° 17:40	9.73	47%	167.2°
2046-02-28 Wed	79	—	unknown	19:45–22:45 (good, 3.0 h)	72.6° 17:35	9.69	37%	154.4°
2046-03-01 Thu	77	—	unknown	19:45–22:45 (good, 3.0 h)	72.6° 17:30	9.64	28%	142.0°
2046-03-02 Fri	74	—	unknown	19:45–22:40 (good, 2.92 h)	72.6° 17:30	9.59	20%	129.7°
2046-03-03 Sat	71	—	unknown	19:50–22:35 (good, 2.75 h)	72.6° 17:25	9.55	12%	117.6°
2046-03-04 Sun	69	—	unknown	19:50–22:30 (good, 2.67 h)	72.6° 17:20	9.5	7%	105.7°
2046-03-05 Mon	67	—	unknown	19:50–22:25 (good, 2.58 h)	72.6° 17:15	9.45	3%	93.8°
2046-03-06 Tue	64	—	unknown	19:50–22:25 (good, 2.58 h)	72.6° 17:10	9.41	1%	82.0°
2046-03-07 Wed	61	—	unknown	19:55–22:20 (good, 2.42 h)	72.6° 17:10	9.36	0%	70.2°
2046-03-08 Thu	60	—	unknown	19:55–22:15 (good, 2.33 h)	72.6° 17:05	9.31	1%	58.3°
2046-03-09 Fri	56	—	unknown	19:55–22:10 (good, 2.25 h)	72.6° 17:00	9.26	4%	46.4°
2046-03-10 Sat	52	—	unknown	19:55–22:05 (good, 2.17 h)	72.6° 16:55	9.22	9%	34.5°
2046-03-11 Sun	44	—	unknown	20:00–22:00 (good, 2.0 h)	72.6° 16:50	9.17	15%	22.3°
2046-03-12 Mon	37	—	unknown	20:00–21:50 (good, 1.83 h)	72.6° 16:50	9.12	23%	10.1°
2046-03-13 Tue	30	—	unknown	20:00–21:35 (good, 1.58 h)	72.6° 16:45	9.07	32%	2.6°
2046-03-14 Wed	23	—	unknown	20:00–20:45 (good, 0.75 h)	72.6° 16:40	9.02	42%	15.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-02-13&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.