| Julian Day |
The Julian Day is a continuous count of days and fractions
thereof from the beginning of the year -4712. |
| UT |
Universal Time or Greenwich Civil Time is based on the
rotations of the Earth. The times of various events, particularly
astronomical and weather phenomena, are often given in "Universal
Time" which is sometimes referred to colloquially, as "Greenwich
Mean Time" (GMT). (see Links for detailed
explanation). |
| UTC |
Universal Coordinated Time - similar to UT but is adjusted
to compensate for the slowing down of the Earth's rotation. |
| Local Time |
PC system clock time. This is assumed to be the current time for
the selected time zone. If your PC clock is 03:00:00 hrs, this is assumed
to be the
time of your selected home city. If you change the city location, this
will be also be the local time for the newly selected location. You have to
change location and time synchronously. |
| Lun |
Abbrevation for lunation number. Each new Moon is a new lunation. Lunation
number 1 began on Jan 17, 1923. |
| Sexagenary Cycle |
The Chinese Lunar Calendar is based on a 60-year cycle
combination of 10 Celestial Stems and 12 Earthly Branches. Sexagenary
Cycle #78[17] means that year is the 78th of the 60-year cycle and
it is the 17th year within that cycle. |
| ICM |
Intercalary month (or leap month). |
| Embolistic or Intercalary Year |
A typical lunar year has 12 lunar months. Lunar years which have
13 lunar months contains an ICM. This is also known as a Lunar leap year.
|
| 1st & 15th Day |
The lunar month starts on the day of the
astronomical new moon (also known as 1st day of lunar month). The 15th day of the
lunar month is 14 days from the start of the lunar
month. Although you could see a full Moon, it does not correspond exactly with the astronomical full Moon.
Only the 1st day of the lunar calendar corresponds to the astronomical
new moon. These 1st and 15th days corresponds to the Chinese
Vegetarian Calendar - ie. dates when the more religious Chinese avoid meat
in their meals. |
| RS (Rel.Size) |
This is the computed relative size of the Moon (instantaneous
Moon-Earth distance vs closest Moon-Earth distance). This is to
give a clue as to how large the Moon is at any instant in time.
Many websites offers a less than satisfactorily explanation as why the
Moon appears larger at time of moonrise than when its overhead. The
general explanation given is "because you are unconsciously comparing
the size of the Moon against the background landscape, so it appears
larger". A recent article explains this phenomenon in great detail -
see "Moon Trivia / Moon
Size" page.
In the 20th Century, the closest and furthest
distance
between Earth-Moon is 356,375km on Jan 4, 1912 and 406,712km on March 2,
1984 respectively. (Meeus: "Astronomical Tables of the Sun, Moon and Planets"
) See also "Moon Trivia" page. |
