on TZtoTZ(TZ1date, TZ1, TZ2)
return (do shell script ("eraTime=$(TZ=" & TZ1 & " date -jf '%Y-%m-%dT%H:%M:%S' '" & (TZ1date as «class isot» as string) & "' '+%s') ; TZ=" & TZ2 & " date -r \"$eraTime\" '+%Y-%m-%dT%H:%M:%S'") as «class isot») as date
end TZtoTZ
set dt1 to date ("26.10.2013 12:00")
set dt2 to date ("27.10.2013 12:00")
(TZtoTZ(dt2, "Europe/Berlin", "GMT") - TZtoTZ(dt1, "Europe/Berlin", "GMT")) / hours --> 25.0
on TZtoTZ(TZ1date, TZ1, TZ2)
return (do shell script ("eraTime=$(TZ=" & TZ1 & " date -jf '%Y-%m-%dT%H:%M:%S' '" & (TZ1date as «class isot» as string) & "' '+%s') ; TZ=" & TZ2 & " date -r \"$eraTime\" '+%Y-%m-%dT%H:%M:%S'") as «class isot») as date
end TZtoTZ
on timeToGMT on dt for TZ
return dt - TZtoTZ(dt, TZ, "GMT")
end timeToGMT
set dt1 to date ("26.10.2013 12:00")
set localTZ to (do shell script ("readlink '/etc/localtime' | sed 's|/usr/share/zoneinfo/||'"))
timeToGMT on dt1 for localTZ
on TZtoTZ(TZ1date, TZ1, TZ2)
return (do shell script ("eraTime=$(TZ=" & TZ1 & " date -jf '%Y-%m-%dT%H:%M:%S' '" & (TZ1date as «class isot» as string) & "' '+%s') ; TZ=" & TZ2 & " date -r \"$eraTime\" '+%Y-%m-%dT%H:%M:%S'") as «class isot») as date
end TZtoTZ
set dt1 to date ("10/26/2013 12:00")
set dt2 to date ("10/27/2013 12:00")
(TZtoTZ(dt2, "Europe/Berlin", "GMT") - TZtoTZ(dt1, "Europe/Berlin", "GMT")) / hours --> 25.0
Setting System Preferences to 24 hour clock didn’t make it work, but adding PM to the times did work.
on TZtoTZ(TZ1date, TZ1, TZ2)
return (do shell script ("eraTime=$(TZ=" & TZ1 & " date -jf '%Y-%m-%dT%H:%M:%S' '" & (TZ1date as «class isot» as string) & "' '+%s') ; TZ=" & TZ2 & " date -r \"$eraTime\" '+%Y-%m-%dT%H:%M:%S'") as «class isot») as date
end TZtoTZ
set dt1 to date ("10/26/2013 12:00 PM")
set dt2 to date ("10/27/2013 12:00 PM")
(TZtoTZ(dt2, "Europe/Berlin", "GMT") - TZtoTZ(dt1, "Europe/Berlin", "GMT")) / hours --> 25.0
Where do you get the locations from like “Europe/Berlin”?
In this particular case, I just used “Europe/Berlin” because that’s what juergen said was his time zone in post #6. One way to get the time zone on the local computer is, as in post #16, to parse the POSIX path pointed to by the symbolic link “/etc/localtime”:
set localTZ to (do shell script ("readlink '/etc/localtime' | sed 's|/usr/share/zoneinfo/||'"))
This was interesting, I started to dig a little into the zoneinfo files that lies below /usr/share.
When I use the command zdump zoneinfo/US/Hawaii I get the current time back, according to the manual, in utc. So, they don’t do much useful, the commands to read tzone files from the shell. I think you’ll have to set the LC_TZ to something for their usefullness to kick in.
I was hoping to get the offset or something, instead I ended up with the knowledge that leap seconds aren’t included in posix time (seconds since epoch.) (man time2posix)
What you’re seeing is correct; you’re just not looking at the full picture. Change your script to this:
set dt1 to date ("26.10.2013 12:00")
set dt2 to date ("27.10.2013 12:00")
log dt1
log dt2
(dt2 - dt1) / hours
Now go to System Preferences, Language & Text, and change the Medium format for time display so that it also includes the timezone. Run the script and look at the logged values. You might now agree with AppleScript
If you want to do much with AS dates, the key is to ignore the string value, and just deal with the underlying components.
It’s better to use the same list as the mac does, that is the IANA Time Zone Database. Here you can download the plain text versions of the files that are serialized in /usr/share/zoneinfo. When downloading these plain text files you can look into these files and see the history of time settings.
I’ll just add to what is written above: I believe there is a way to decompile the zoneinfo files. but zdump gives you some output, zdump -v exactly what DJ Bazzie Wazzie said. You should get further pointers by looking at man zdump.
As a user, the most usage you have of the zone-info database is the timezone names really, and you’ll use those to set the TZ variable with them, then use the date to see the new time. Perfect for making a world clock with AppleScript. Berlin London Paris New York Tokoyo.
It’s equivalent to the “yyyy-mm-dd” part. The time part can be obtained with “%T”. So in my TZtoTZ handler, “%Y-%m-%dT%H:%M:%S” can be reduced to “%FT%T”. Thanks for the heads-up!
The formatting is actually done by strftime.
on TZtoTZ(TZ1date, TZ1, TZ2)
return (do shell script ("eraTime=$(TZ=" & TZ1 & " date -jf '%FT%T' '" & (TZ1date as «class isot» as string) & "' '+%s') ; TZ=" & TZ2 & " date -r \"$eraTime\" '+%FT%T'") as «class isot») as date
end TZtoTZ
Time has always been a nuisance, just ask the slave serving under the tyrant of scicily, when said tyrant, moved the time stone higher up, for getting more daylight on it, and hence prolong the working hours.
And the watch makers of Florence, who got their eyes stabbed out by angry factory workers that suddenly, had to follow the clock, and abandon daylight governing the length of their workday. But, the utilization of the clock, made Florence the most productive creator of fabrics from the weaveries, and made her prosper.
Our problems seems meagre. (Especially with Nigel’s handlers.)