LMT versus standard time

[Butterfly]

Even as I write that it doesn't make a lot of sense to me.
An astrologer I was talking to said that she was taught to use LMT (local meridien time?) as opposed to the standard time and has found it to be much more accurate.
Can anyone enlighten me on LMT? Does the fact that she was from Australia and therefore the Southern Hemisphere affect this? Eek!

 

[AquarianGoddess]

Hi Butterfly,

Such a "cerebral" question on a day when my brain is on vacation!

LMT is Local Mean Time...and that's as much as I remember from the dayz of doing the math long-hand.

Astrologers (or really, computers nowadays) deal with many different kinds of time...

UT is universal time

GMT is Greenwich Mean Time

ST is Sidereal Time

All are used when computing a chart. The specific time of where a person is born, i.e., eastern standard, or central european, is also used.

That's the best I can do for now. Perhaps if Minderwiz drops by, he or she can give you a better explanation, or I can dig out my very, very old notes!

AG

 

[debins]

Curious...

and thanks for the question. I had read that astrologers convert birth time to GMT in order to create a sort of level playing field. Is this so?
Namaste,
Debins.

 

[AquarianGoddess]

Yes, Debins, that is correct. After a few conversions, we wind up with Sidereal Time which determines the ascendant and cusps.

Wow, this brings back memories!!

 

[Butterfly]

Boing!!

It's all fallen into place in my brain, thanks to Alan Okens gem of a book!OK, now it doesn't affect the planets at all. They're calculated with GMT. Got it!
But when it comes to Ascendent, Midheaven, house cusps etc- this is where LMT can be more accurate. Now standard time- which is how they are usually calculated is the time zone you are in eg I'm Eastern Australian time (GMT+ whatever hours). LMT makes a slight adjustment for the difference between where I was actually born and where the standard time meridien is, so it represents True Local time.
Now this can affect the sign of the ascendent, midheaven, descendant and nadir as well as the house cusps.
I understand now why this would be more accurate, it makes sense. Don't know if the computer calculated charts take LMT into account. Anyone know?
LOL, sorry if I sozzled anyones brains!

 

[AquarianGoddess]

Yes, most computer generated charts are calculated exactly, dependant on the program. Years ago, when the first astrology programs were born, many of them weren't accurate... and just like computers, they've come a long way.


AG

 

[Minderwiz]

Hi,

I've been on holiday so I missed this thread! An Ephemeris usually publishes the position of planets in terms of either midnight or noon GMT (Universal Time) because to do so for all time zones and all times would make the book impossible to use.

However people's birth times are recorded in terms of Local Time - for example if you were born in New York your time of birth will be recorded in terms of Eastern Standard Time five hours behind GMT. Thus the planetary positions will need to be translated from EST into GMT in order to use the Ephemeris (taking care to allow for any daylight saving that might be operating).

The above calculation is not fully accurate, Strictly speaking the 5 hour time difference only applies to a longitude of 75 degrees West of Greenwich. The local mean time as measured by the position of the Sun, changes by one hour for each 15 degrees of longitude you move. So a point on the Earth's Service with a longitude of 75 degrees West will be 5 hours behind GMT. At 12 noon GMT its Local Mean Time will be 7:00 a.m.

LMT does not just work in units of one hour, it can work in units of single degrees or even minutes of a degree - so New York which has a longitude of 74 degrees 23 minutes West has a Local Mean Time of 4 hours, 57 minutes and 32 seconds ahead of GMT.

Atlanta Georgia which also uses EST but has a longitude of 84 degrees 45 minutes West, has a LMT of 5 hours 39 minutes behind GMT, so two births both recorded at, say 12:00 EST but one in New York and the other in Atlanta will have significantly different LMTs

Correcting for the time of birth and Local Mean Time, enables the positions of the planets at the time of birth to be calcuated from those listed in the Ephemeris. This process basically involves translating the GMT time of birth into a fraction of a day, for example if the birth time occured at exactly 18:00 GMT this would be 0.75 of a day. Then calculate the movement of the planets from the midnight position immediately preceding the birth to the midnight position immediately after the time of birth. Multiply this movement by 0.75, add it to the first midnight position and you get the positions at the exact time of birth. Now you know why astrologers use computers rather than paper and pencil!

Regards

Minderwiz

PS AG, I'm a fella!

 

[AquarianGoddess]

OKAY, OKAY...sorry MR. Minderwiz!!

Love,
AG