WSPR MAP - DAY/NIGHT Overlay is about one hour advanced over real day / night position

8 posts / 0 new
Last post
G0BZB
Online
Last seen: 3 min 5 sec ago
Joined: 2011/04/24 - 21:33
WSPR MAP - DAY/NIGHT Overlay is about one hour advanced over real day / night position

It's great that the day night overlay has been working for a while now. Thanks to whoever (Bruce?) fixed it. But - I've been noticing that since we moved the clocks forward to Summertime settings, the day night terminator is over advanced. I notice this by eye, looking out of the window when the map shows us on the greyline, but also by comparing the WSPR greyline to this one:

http://www.fourmilab.ch/cgi-bin/Earth?img=learth.evif&imgsize=320&opt=-p...

It looks like the over advance is about one hour. Thinking about this, I'm wondering where the code gets the time from. Maybe if it is taking the code from my PC clock, corrected for summertime (one hour forward of UTC) then that might account for the issue. Of course, I could be totally wrong about where the code gets the time from. It might be from a central server somewhere, and I am talking nonsense.

Anyway, I thought I'd bring this up in case anybody has an idea about what is causing the inaccuracy and something can be done to sort the problem.

73s

de G0BZB

Tony