Hi Bill,

I was trying to enter this date/time in Guide in Dynamical Time
14 aug 2557 12:26:30,8 TD = JD 2655211.0184120 TD

And I noticed something a bit strange about Delta T and time zone.

When selecting in the time menu Time Zone = Dynamical Time TD, I expected that I could enter a julian day in Dynamical Time with the JD button.
But it looks like the Julian day always remains in UT Time. When I look at the quick info I have for example :

Quick info for 14 aug 2557 12:26:31:TD (JD 2655211.00444) (Delta T = 1207.7 secs)

The quick info thus matches a TD time with a UT julian day !


Actually In UT (with your value 1207.7 for Delta -T) we have :

14 aug 2557 12:06:23,1 UT = JD 2655211.0044340 UT

and in TD

14 aug 2557 12:26:30,8 TD = JD 2655211.0184120 TD


If, in the time menu, I choose time zone = TD and I enter the date 2655211.0184120 with the JD button, Guide recalculates the time and displays 14 aug 2557 12:46:38. I should have entered JD = 2655211.004434 (UT) to get 12:26:30 (TD).

This is not really a problem if you are aware of it, just a bit surprising. Perhaps a small note in the quick info box or/and in the time box could help ?

Regards,

Luc






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