Time keeping specifications for the round face Classic YES watches.

Following is a summary of the time data offered:

• Hours, minutes and seconds in AM/PM or 2400 format.
• 24-hour flashing digital hand.
• Noon on top, midnight on bottom.
• Month, date and day.
• Year, day of year and week number.
• Times for sunrise, sunset and solar high noon.
• Sunrise and sunset alarms 1/2 hour before and at event.
• Equinox, solstice and cross-quarter alerts.
• Moonrise, moonset and moon phase.
• Percentage lunar illumination.
• Time and date for next new and full moons.
• Past / future date calculator for sun, moon and time data.
• Time data capability for the years 2000-2099
• Regular set alarm with 10-minute snooze.
• 24-hour stopwatch with lap time.
• 99-minute timer with alarm.
• 9999-day count down / count up for set event time / date with alarm.
• Programmed for 583 cities worldwide
• Keeps digital time for 2 locations, HOME and AWAY.
• 24-hour bezel can be used to keep time for a third time zone.
• Location can also be set by latitude and longitude, time zone and one of 5 major DST systems.
• Automatically adjusts for Daylight Saving Time worldwide.
• DST can be set or adjusted manually.
• Backlight for night time viewing.
• Digital time can be turned off.

The v4 mother board is a tightly packed design connecting the chip with the LCD, quartz oscillator, transistors, EL light, alarm and other functions.

Based on complex astronomical algorithms using UTC time reference and whole degrees of latitude and longitude, the YES watch calculates sun, moon and time data once every 24 hours, at midnight HOME time.

We used algorithms published by the US Navy and Jean Meeus. An astronomer converted them into suitable language for programming.

Since every degree of longitude represents 4 minutes the sun and moon calculations carry an accuracy of +/-2 min. Since the moon waxes or wanes approximately 4% every day, 1% of illumination is about 6 hours.

Equinoxes, solstices and cross-quarter dates are subject to some cultural interpretations, so in our calculations we chose a mathematical mid-point between equinox and solstice.

The analog Swiss hand movement is manufactured to plus 10 / minus 20 seconds a month. The Japanese digital quartz chip is specified to plus / minus 20 seconds a month.

Each sun and moon segment in the LCD display represents 15 minutes.

Each sliver in the moon phase display represent about 44 hours.

The Time Ball

As pocket watches came into use in the early 1800's, there was a clear need for an accurate reference point by which they could be set. Dipping a flag, firing a gun or eclipsing a search light were predssecors to the time ball. Starting in1833 an astronomer would accurately pin point thesolar high noon and then at 1 o'clock PM the ball would be dropped. Placed in towers high above rivers and towns it could be seen far and away and was one of the first methods to disperse a uniform time signal.