Time zones and Daylight savings in AF/D

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DaveInPA

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Dave
I have a feeling this is often asked but my search didn’t resolve my confusion....

In the AF/D entry for an airport it shows the local time conversion such as UTC-8(-7 DT). Then in the rest of the entry it might show when the tower is operating with the Zulu time (1400-0600++) with the plus plus symbol being rotated. The legend says when that symbol is there and it’s daylight savings time you should subtract an hour.

So do I convert using 8 or 7 during DST and then one more hour? The (-7 DT) part doesn’t make any sense to me...
 
It means the tower doesn’t have clocks that are resettable, so they don’t go on DST. ;)

in your example, tower is always UTC-8.
 
So....

- in winter it’s 1600-8000 = 8am local time
- in summer it’s 1600-7000 = 9am but then apply ++ and it’s 8am

I’m other words just ignore the DT and ++ as the tower is always open at 8am regardless. The -7DT is there as a convenience to set your watch when you land. The ++ is a reminder that if you convert the tower time from Zulu to local apply the DST factor.

or like I said just ignore all that and tower times are the same locally all year...
 
Phew. The conversion factors are from UTC to local. The ++ reminds you to subtract one hour from the listed UTC times if it's daylight time, since daylight time is an hour closer to Greenwich.
 
dtuuri said:
Phew. The conversion factors are from UTC to local. The ++ reminds you to subtract one hour from the listed UTC times if it's daylight time, since daylight time is an hour closer to Greenwich.
Click to expand...
Larry in TN said:
That, right there, is funny.
Click to expand...
That'd drive a C/C++ programmer slightly nuts :)
 
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