A5.209.1.8 Multilevel Astronomical Time-Switch Controls

Multilevel astronomical time-switch controls used to control lighting in daylit zones shall:

1. Contain at least two separately programmable steps per zone that reduces illuminance in a relatively uniform manner as specified in Section A5.209.2.2; and
2. Have a separate offset control for each step of 1 to 240 minutes; and
3. Have sunrise and sunset prediction accuracy within +/- 15 minutes and timekeeping accuracy within 5 minutes per year; and
4. Store astronomical time parameters (used to develop longitude, latitude, time zone) for at least 7 days if power is interrupted; and
5. Display date/time, sunrise and sunset and switching times for each step; and
6. Have an automatic daylight savings time adjustment; and
7. Have automatic time switch capabilities specified in Section A5.209.1.3.