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PRTimeParameters
================
A representation of time zone information.
Syntax
------
.. code::
#include <prtime.h>
typedef struct PRTimeParameters {
PRInt32 tp_gmt_offset;
PRInt32 tp_dst_offset;
} PRTimeParameters;
Description
-----------
Each geographic location has a standard time zone, and if Daylight
Saving Time (DST) is practiced, a daylight time zone. The
:ref:`PRTimeParameters` structure represents the local time zone
information in terms of the offset (in seconds) from GMT. The overall
offset is broken into two components:
``tp_gmt_offset``
The offset of the local standard time from GMT.
``tp_dst_offset``
If daylight savings time (DST) is in effect, the DST adjustment from
the local standard time. This is most commonly 1 hour, but may also
be 30 minutes or some other amount. If DST is not in effect, the
tp_dst_offset component is 0.
For example, the US Pacific Time Zone has both a standard time zone
(Pacific Standard Time, or PST) and a daylight time zone (Pacific
Daylight Time, or PDT).
- In PST, the local time is 8 hours behind GMT, so ``tp_gmt_offset`` is
-28800 seconds. ``tp_dst_offset`` is 0, indicating that daylight
saving time is not in effect.
- In PDT, the clock is turned forward by one hour, so the local time is
7 hours behind GMT. This is broken down as -8 + 1 hours, so
``tp_gmt_offset`` is -28800 seconds, and ``tp_dst_offset`` is 3600
seconds.
A second example is Japan, which is 9 hours ahead of GMT. Japan does not
use daylight saving time, so the only time zone is Japan Standard Time
(JST). In JST ``tp_gmt_offset`` is 32400 seconds, and ``tp_dst_offset``
is 0.
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