I was looking for the time of sunset the other day. My clocks don't have numbers small enough for sunrises so their time is pretty much irrelevant for me. Anyway, I figured an Almanac program would be a good place to look for information like that. But the times it listed were off the wall so I figured they must be UT, but applying our offset only made matters worse. So I tried another iPad program or three and found that the programs that did list reasonable times did not always agree. That got me looking into all of the programs that I have that list sunrise and sunset times. I found that there was better agreement among the various programs about what time the Sun would wake up than what time he would go to sleep. Some variation may be due to some programs using GPS/IP location which is not always accurate while others may pull my location from a database, and not all of them think NYC is in the same place. But I would expect those errors to be in the neighborhood of seconds and deoending on how each program deals with the seconds (rounding vs. truncating) that might introduce a difference of a minute. It would seem that the algorithm for calculating these times should be a known standard and that all programs should come up with the same times.
| Program | Sunrise | Sunset |
|---|---|---|
| US Naval Observatory | 0632 | 1745 |
| SkySafari | 0632 | 1745 |
| Star Walk | 0632 | 1745 |
| SkyORB | 0630:18 | 1745:40 |
| GoSkyWatch | 0631 | 1745 |
| Distant Suns 2 | 0631 | 1745 |
| LightTrac | 0632 | 1746 |
| Sun Moon | 0631 | 1748 |
| Sky Almanac | 0111 | 1211 |
| Twilight Moon | 0632 | 1746 |
| Daylight Cal | 0632 | 1740 |
| Mr Sun | 0632 | 1745 |
| Golden Light | 0632 | 1745 |
| Sunrise & Sunset | 0631 | 1745 |
| Magic Hour | 0632 | |
| Emerald Observatory | 0631 | 1743 |
| Planets | 0632 | 1745 |
| Grand Tour | 0938 | 2059 |
Today is one of those days during the year where the date and time form interesting patterns. I forget what the official name for this class of events is or for this pattern in particular but the name natiomer, for a chemical compound that comes in two mirror imag forms, has always stuck with me and if today were a chemical compound it would be a natiomer.
Sunspots
Observing Hours for the Year 2012
| Day | Night | Total | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Hours | Days | Avg | Hours | Days | Avg | Hours | Days | Avg | |
| Jan | 0.00 | 0 | 0.00 | 1.00 | 1 | 1.00 | 1.00 | 1 | 1.00 |
| Feb | 6.75 | 6 | 1.13 | 13.75 | 6 | 2.29 | 20.50 | 9 | 2.28 |
| TOTAL | 6.75 | 6 | 1.13 | 14.75 | 7 | 2.11 | 21.50 | 10 | 2.25 |
| Days With Observing | Time Spent Observing | |
|---|---|---|
| Jan12 | 3.23% | 0.13% |
| Feb12 | 31.03% | 2.95% |
| 2012 To Date | 16.67% | 1.49% |
