The Night Clock - To use, place a counter on the time. Move it as time progresses in game. When players split up use a different counter for each player. This version is for NYC only. The daylight savings adjustment is not included. The twilight period varies through the year and the coloured boxes cover that variation. To figure out when night ends for a date split the box into 6 equal segments, one for each of the months between Jun 21st and Dec 21st. Thus Morning Twilight on 21st Jun starts at 4:50 (ish) and ends when the sun is actually up at 5:20 (ish)
