With inspiration drawn from the ancient Greek Antikythera mechanism – a complex mechanical clock from 150-100BC that detailed the position of the moon and stars for a given date – Khronos is a new app developed by Quadrivium Ltd that functions as a true multicultural timepiece. Khronos integrates the Gregorian, Hebrew and Islamic calendars as well as the Japanese and Buddhist eras with astronomical data to provide a unique view of time in relation to celestial movements and events.
The main screen in Khronos displays a complex arrangement of information that relates the date and time as well as the position of astronomical bodies such as the sun, moon and planets. There are a several rings, lines and inner circles that appear overwhelming. at first glance. It’s worth taking a look at the comprehensive help section to better understand the various elements of the clock.
The clock itself does not display the time per se – the exact digital time is given on the top of the screen. Instead, the hands of the clock give directional and astronomical information. There are two main ‘hands’ – the sun hand and the compass North arrow. The sun hand follows the sun around the compass from East to West, completing one full circle each day. The North arrow will automatically orient itself for owners of an iPhone 3GS – previous iPhone users can ascertain True North by directing the sun hand at the actual sun.
The two outermost rings of the clock show the months of the year using two selected calendars. The inner ring contains the primary calendar and determines when the cycle begins and ends – which will be different depending on which calendar is selected (Islamic, Hebrew, Gregorian etc). You can also enter a particular date in one calendar e.g standard Gregorian (Jan-Dec) and view the corresponding date or era in another calendar e.g Hebrew or Buddhist.
The position of the major planets are shown, represented by symbols, including Mercury, Venus, Mars, Jupiter and Saturn. Color is used to show the elevation of the planet relative to the horizon. White denotes a body high in the sky, yellow/red denotes close to the horizon while purple/blue reflects a body below the horizon. The ‘Sky Ring’ on the clock shows the current position and phase of the moon. In addition to astronomical positions, perpendicular lines lying across the clock face show the timing of Soltices and Equinoxes in relation to the zodiac constellations and dates upon which they fall.
You also have the option of customizing the appearance of the clock – double tapping on the center of the clock will bring up a number of options concerning overlays and display options.
Bottom Line: Khronos is a useful app, albeit a tad expensive at $7.99. Grea for anyone with an interest in, or need for different calendar systems or the identification of astronomical bodies and events.
Khronos requires the iPhone OS 3.0 or later and is compatible with both the iPhone & iPod Touch.