timezones...

[Steve]

I'm going slowly mad here... What I want to do is to be able to convert
from a timezone name eg "Europe/London" to an offset from UTC ... in
this case it's +1 hour at the moment. The end result is to convert an
utc timestamp held in a mysql database into a display field in the
relevant local time ( not doing so can be most tedious when you live in
GMT+12! ).

There must be a simple way... I've got linux and mysql available if
either of these help.

Cheers,


Steve

[Jasper Bryant-Greene]

Re: timezones...

Steve wrote:[color=blue]
> I'm going slowly mad here... What I want to do is to be able to convert
> from a timezone name eg "Europe/London" to an offset from UTC ... in
> this case it's +1 hour at the moment. The end result is to convert an
> utc timestamp held in a mysql database into a display field in the
> relevant local time ( not doing so can be most tedious when you live in
> GMT+12! ).[/color]

Just a stab in the dark as I don't have a Linux box handy to test this
on, but shouldn't the files in (from memory) /usr/share/zoneinfo have
offsets in them?

They are named by timezone name and could just be accessed via
file_get_conten ts.

--
Jasper Bryant-Greene
Cabbage Promotions

[Steve]

Re: timezones...

Jasper Bryant-Greene wrote:[color=blue]
> Steve wrote:
>[color=green]
>> I'm going slowly mad here... What I want to do is to be able to
>> convert from a timezone name eg "Europe/London" to an offset from UTC
>> ... in this case it's +1 hour at the moment. The end result is to
>> convert an utc timestamp held in a mysql database into a display field
>> in the relevant local time ( not doing so can be most tedious when you
>> live in GMT+12! ).[/color]
>
>
> Just a stab in the dark as I don't have a Linux box handy to test this
> on, but shouldn't the files in (from memory) /usr/share/zoneinfo have
> offsets in them?
>
> They are named by timezone name and could just be accessed via
> file_get_conten ts.
>[/color]
not that simple...

/usr/share/zoneinfo/Europe/London is a binary file. zdump will give me
the current time there. but i still need to calculate the offset from utc!

Steve

[Jasper Bryant-Greene]

Re: timezones...

Steve wrote:[color=blue]
> not that simple...
>
> /usr/share/zoneinfo/Europe/London is a binary file. zdump will give me
> the current time there. but i still need to calculate the offset from utc!
>
> Steve[/color]

Subtract UTC from current time there and you will have the offset.

--
Jasper Bryant-Greene
Cabbage Promotions

[Brion Vibber]

Re: timezones...

Steve wrote:[color=blue]
> I'm going slowly mad here... What I want to do is to be able to convert
> from a timezone name eg "Europe/London" to an offset from UTC ... in
> this case it's +1 hour at the moment. The end result is to convert an
> utc timestamp held in a mysql database into a display field in the
> relevant local time ( not doing so can be most tedious when you live in
> GMT+12! ).[/color]

PHP's date() function can give you the timezone offset in seconds. You
can set the current timezone by setting the TZ environment variable
(putenv() and getenv()).

-- brion vibber (brion @ pobox.com)

[Steve]

Re: timezones...

Brion Vibber wrote:[color=blue]
> Steve wrote:
>[color=green]
>> I'm going slowly mad here... What I want to do is to be able to
>> convert from a timezone name eg "Europe/London" to an offset from UTC
>> ... in this case it's +1 hour at the moment. The end result is to
>> convert an utc timestamp held in a mysql database into a display field
>> in the relevant local time ( not doing so can be most tedious when you
>> live in GMT+12! ).[/color]
>
>
> PHP's date() function can give you the timezone offset in seconds. You
> can set the current timezone by setting the TZ environment variable
> (putenv() and getenv()).
>
> -- brion vibber (brion @ pobox.com)[/color]
Brion... perfect!

The few grey hairs I have left thank you too!

Cheers,

Steve

[Steve]

Re: timezones...

Brion Vibber wrote:[color=blue]
> Steve wrote:
>[color=green]
>> I'm going slowly mad here... What I want to do is to be able to
>> convert from a timezone name eg "Europe/London" to an offset from UTC
>> ... in this case it's +1 hour at the moment. The end result is to
>> convert an utc timestamp held in a mysql database into a display field
>> in the relevant local time ( not doing so can be most tedious when you
>> live in GMT+12! ).[/color]
>
>
> PHP's date() function can give you the timezone offset in seconds. You
> can set the current timezone by setting the TZ environment variable
> (putenv() and getenv()).
>
> -- brion vibber (brion @ pobox.com)[/color]

....it's so simple, here's my solution.

<?
function GetOffset ( $TimeZone )
{


//Save the current setting
$SaveZone = getenv ( "TZ" );
putenv ( "TZ=$TimeZo ne" );
$Offset = date ( "Z" );
putenv ( "TZ=$SaveZo ne" );


echo "$TimeZone is $Offset seconds from UTC\n";
return $Offset;
}
GetOffset ( "Pacific/Auckland" );
GetOffset ( "Europe/London" );
?>