Sundial Necklace - Ra Series - "Seba-djai"

Works(if you know which way is south), is awesome.

If you hold at roughly the correct angle, and if you know whether it's morning or afternoon, all you have to do is turn until the shadow falls on the side, and it will not only tell you the time, but you will automatically be facing south. (If the shadow falls on the morning side but you know it's afternoon, or vice versa, you have to turn a different direction.)To eyeball the correct angle, take 90 degrees minus your latitude. My latitude is 40 degrees, so I start by holding it at about 50 degrees from the horizontal, for spring and autumn. In midsummer add 20 degrees, so I'd hold it at about 70 degrees. In midwinter subtract 20 degrees, so I'd hold it at about 30 degrees from the horizontal. But because it's so small, the angle doesn't have to be even close to being exact. The time will probably only be accurate to within half an hour anyway. And of course if Daylight Savings Time is in effect, you'll have to add an hour.I've been collecting and using portable sundials for decades. I love how simple and easy to use this one is.