Daily times for "daylight" conditions

This page deals with the "lighting" conditions. At the bottom of the page is a detailed table of Sun and Moon times and phases, given in modern local timings, including daylight savings times. Also note that, as far as times went - the Germans were using Berlin time, which is two hours ahead of local (daylight saving) time in Kursk. I have, to date, assumed that the Soviets were working on local time, including daylight saving. In summary:

The sun - daylight

Actual sunrise was around 05:30, with "dawn" at 04:30, drifting to 04:55 on the 19th July. At "dawn" we are into the period of "morning twighlight" where, in good weather, objects can begin to be reasonably distinguished. The "first light" is at around 03:30, drifting to 03:50 on the 19th. At this point, shapes become visible, but general outdoor operations are not possible.

For the end of the day, sunset was around 21:50, with "dusk" at 22:30, drifting to 22:20 by the 19th and "last light" at 23:55, drifting to 23:30.

So - on the 10th July 1943, if the weather was good, first light was at 03:34, with objects on the Eastern horizon starting to become visible, dawn was at 04:43, when the troops could begin to find - and use - their weapons, with sunrise at 05:29. The sun set again at 21:51, with dusk at 22:31 and last light at 23:45. They were long days out there on the Steppes ! Fighting quite possible from 04:43 to 22:31 - 17 hours and 48 minutes.

The moon - visibility at night

There are two important factors to the moon - rise/set times - and the phase.

Moon rise is at 06:15 and set at 22:19 on the 3rd, moving to rise at 22:57 on the 19th, setting at 07:54 the next morning.

But: the moon's phase (the "Phase %" in the table) starst at 0% on the 3rd July 1943 - there was no moon that night. The opening moves went in on the night of the 4th - with only 2% moonlight - almost pitch darkness. By the 10th, the moon was almost at 50% - but it rose during the day and set at 01:03 the next morning, giving only 2 and a half hours of moonlight after dusk, before total darkness again.

So - just how much light ?

And how much light does the moon give ? The moon has an albedo of 7% - a full moon gives 7% of the light of the sun in daylight. This is enough to move around by - it is like the light at "dusk". The table below gives a set of measurements (in candelas - go look it up !), for the amount of light visible at certain times of the day:

**Approximate Luminance of the sky near the **horizon** in cd/m²**
Environment	Luminance Level
Clear sky at noon	10^4
Cloudy sky at noon	10^3
Grey sky at noon	10^2
Cloudy sky at sunset	10
Clear sky, a quarter hour after sunset	1
Clear sky, a half hour after sunset	10^-1
Night sky - Full moon	10^-2
Night sky - Clear without moon	10^-3
Night sky - Cloudy without moon	10^-4

And, to put that in perspective... the Absolute threshold for seeing light is 10^-6 cd/m², with colour vision starting at 10^-3 cd/m² and damage starts to occur at 10^8 cd/m².

Note that the same table is represented graphically on the day-by-day account pages and summarised here.

		Sun						Moon
Date		First	Dawn	Rise	Set	Dusk	Last	Rise	Set	Phase
Saturday	3-Jul-43	03:23	04:36	05:23	21:55	22:35	23:54	06:15	22:19	0%
Sunday	4-Jul-43	03:25	04:37	05:24	21:55	22:35	23:53	07:08	22:56	2%
Monday	5-Jul-43	03:26	04:38	05:24	21:54	22:34	23:52	08:06	23:28	5%
Tuesday	6-Jul-43	03:28	04:39	05:25	21:54	22:34	23:51	09:06	23:55	10%
Wednesday	7-Jul-43	03:29	04:40	05:26	21:53	22:33	23:49	10:09	23:55	17%
Thursday	8-Jul-43	03:31	04:41	05:27	21:53	22:32	23:48	11:12	00:19	25%
Friday	9-Jul-43	03:33	04:42	05:28	21:52	22:31	23:47	12:17	00:42	34%
Saturday	10-Jul-43	03:34	04:43	05:29	21:51	22:31	23:45	13:23	01:03	43%
Sunday	11-Jul-43	03:36	04:44	05:30	21:51	22:30	23:44	14:31	01:25	53%
Monday	12-Jul-43	03:38	04:45	05:31	21:50	22:29	23:42	15:42	01:49	64%
Tuesday	13-Jul-43	03:40	04:47	05:32	21:49	22:28	23:40	16:55	02:16	74%
Wednesday	14-Jul-43	03:42	04:48	05:33	21:48	22:27	23:39	18:09	02:48	83%
Thursday	15-Jul-43	03:44	04:49	05:34	21:47	22:26	23:37	19:22	03:29	91%
Friday	16-Jul-43	03:46	04:51	05:35	21:46	22:25	23:35	20:30	04:19	96%
Saturday	17-Jul-43	03:48	04:52	05:37	21:45	22:23	23:33	21:29	05:21	100%
Sunday	18-Jul-43	03:50	04:54	05:38	21:44	22:22	23:31	22:17	06:34	100%
Monday	19-Jul-43	04:52	04:55	05:39	21:43	22:21	23:29	22:57	07:54	97%

Source: Astronomical Applications Dept.
U. S. Naval Observatory
Washington, DC 20392-5420
http://aa.usno.navy.mil/AA/data/docs/AltAz.html