Midnight GMT positions (Tropical) for 1700-2100 are derived from the JPL (Jet Propulsion Laboratories) DE406 ephemerides and the US Naval Observatory equivalent for Asteroids. These are stored in a small binary database of our own devising. From that database positions for any other time/timezone are interpolated using the algorithms specified by Jean Meeus. Sidereal positions are derived by correcting the Tropical positions for the users selected or provided Ayanamsa.
iPhemeris uses a "New Style" calendar with all dates being according to the Gregorian Calendar adopted October 1582. However, be aware that some locales adopted the Gregorian calendar at other times; for example, Great Britain switched in September 1752. Therefore you may have to adjust your dates accordingly.
Tabs at the bottom of the display can be re-arranged any time you like.
The Settings menu offers many options for customizing iPhemeris according to your needs and preferences. You should spend a little time and review all the settings because they provide quite a bit of flexibility and control over the way it works.
The Transits Calendar displays a monthly calendar of Transits to the selected Chart in your Chart library. Starting with Version 8.4 of iPhemeris this is the ONLY way to set the event chart used by Transit Calendar.
Chart defaults are used when setting up new Charts. To change settings for existing charts, edit the chart details from the Charts tab.
iPhemeris has 2 default settings for independently controlling the Progression style used for planets and house cusps (Angles). These apply to new charts but can be changed for individual chart by editing the chart details from the Charts tab (see the section on chart drawing for details).
iPhemeris currently supports the most common Progression techniques. More will be added soon.
The Sky Now and Houses Now features are real time Astrological clocks updating every 15 seconds and which show respectively a Chart of the the sky with Aspect Grid, and a Table of Houses for your current location and time.
By default these use the devices location and continuously update latitude and longitude. If you prefer you can lock them to the location specified in the Latitude and Longitude fields, for example the New York Stock Exchange.
The House system used by Sky Now and Houses Now.
Setting up new charts is fastest if you enter the data in the order of the fields.
The Aspectarian shows the relationship between bodies in the sky on a particular date. For example the Sun relative to Saturn on the same date.
It is possible to move the iPhemeris chart database between iOS devices, however you must be careful when doing this else you will render your charts unusable.
Follow these guidelines to prevent damage to the iPhemeris chart database:
To move data to another device follow these steps:
WARNING: When you do this you are completely replacing the charts on second device with charts from the first.